is an SSD upgrade, really worth it considering my usage?

I would not spend $10 on a 10 year old computer so my answer is no. If it still runs okay just continue to use it. However, PLEASE make sure you are backing it up daily using Time Machine. A 10 year old computer could fail at any time so you need to safeguard your data.

In case you are not already using Time Machine please click Back up your Mac with Time Machine, and if you need a Time Machine External Hard Disk many experienced users on these forums recommend the https://eshop.macsales.com/shop/owc-mercury-elite-pro

A healthy Fusion drive can be faster than some of the SSD options. Your Fusion drive should be doing about 600-900MB/sec Writes and over 1300MB/sec Reads. The most common and cheapest USB external SSD solution only does 400MB/sec for both.

If you use EtreCheck to survey your computer and post the result here, we can see hard data on your current drive performance and better advise you on an action plan than when we have zero idea of your current drive performance and condition..

The report will also show if the Fusion drive is slow because it is "split," something that is fixable at home without pro help.

Right now we have to guess (we're not very good at guessing!). EtreCheck Pro is the only way for us to get hard data on your system in this limited support setting. It is available here:

https://etrecheck.com/index

The free version will do nicely for this purpose, although the app is worthy of our financial support.

We can see hard data about drive performance, software issues, and RAM usage. Sometimes slow issues are due to useless extra software. EtreCheck is the development of a long-serving and trusted contributor here expressly for displaying information in these forums to help us help you by remotely evaluating Mac issues. It will not reveal any personal or secure information.

Please see this excellent user tip on how to post long text reports like EtreCheck's into a forum response:

How to use the Add Text Feature When Post… - Apple Community

You can always use an external SSD as your main boot drive. You can get an SSD and an enclosure and clone your internal drive to the external using an app like Carbon Copy Cloner. I would not expect any hardware failures from your present Mac as Apple lasts a long time.

Considering your usage pattern and the fact that you don't feel the Mac is running slow, upgrading to an SSD may not show a drastic improvement for the tasks you mentioned. However, there are a few factors to consider before making a decision:

Benefits of Upgrading to an SSD:

1. Speed and Responsiveness:

- SSDs are significantly faster than traditional HDDs or Fusion Drives. You would experience faster boot times, quicker application launches, and improved overall system responsiveness.

2. Reliability:

- SSDs have no moving parts, making them more durable and less prone to mechanical failure than HDDs.

3. Energy Efficiency:

- SSDs generally consume less power than traditional hard drives, contributing to energy efficiency.

Considerations:

1. Cost:

- SSDs are more expensive per gigabyte compared to HDDs. If cost is a significant factor and you're satisfied with your current system's performance, you might weigh the expense against the perceived benefits.

2. Storage Capacity:

- Ensure the SSD you choose has sufficient capacity for your needs. If you currently use only 40% of your 1TB Fusion Drive, you might not need a large SSD unless you plan to store more data in the future.

3. Potential SSD Failure:

- While SSDs are generally reliable, they can fail. However, modern SSDs have become more robust, and the likelihood of failure is low compared to older models.

OS Reinstallation:

1. Performance Improvement:

- Reinstalling the OS on your current Fusion Drive might improve performance to some extent, especially if there is accumulated clutter over the years. It's a less expensive option compared to an SSD upgrade.

2. Malware and Viruses:

- A clean OS installation can help remove any potential malware or viruses that might have accumulated over the years. It's a good practice for maintaining system health and security.

Recommendations:

1. Assess Budget:

- Consider your budget. If you have the financial flexibility and value the potential performance boost, upgrading to an SSD might be worth it.

2. Evaluate Future Needs:

- Consider your future storage needs. If your data usage is likely to increase, getting a larger SSD might be a good investment.

3. Backup Important Data:

- Before making any changes, ensure you have a reliable backup of your important data. This is crucial, especially if you decide to replace the Fusion Drive with an SSD.

4. Professional Opinion:

- If you're unsure, consult with an Apple professional or a reliable technician. They can assess your specific situation and provide tailored advice.

In summary, given your light usage and current satisfaction with performance, a clean OS reinstallation might be a reasonable first step. If you still find the system lacking, consider the SSD upgrade based on your budget and future storage needs. Always back up your data before making significant changes to your system.

What would fail next is impossible to say, however good candidates are:

• Main Logic Board
• GPU
• Power Supply
• Display
• Display backlighting

Also just to add that your fusion design is probably less reliable than just an SSD alone.

Google Chrome Helper (Renderer) (14) 12.28 % (Google LLC)

That's a lot of CPU demand, and not atypical of Google. Most likely, you will find it or other Google processes far exceed that amount at intervals, resulting in poor observable performance.

If you are required to use Google products, in your case replacing your Fusion Drive with a SSD will go a long way toward managing Google's ever-increasing, automatically-updating demands on fixed hardware that cannot otherwise be updated to cope with them.

If you are not required to use Google products, then don't. I have Macs much older than yours and they perform well. None of them have Google installed (nor will they, ever).