MacBook Pro battery life

When you first get a Mac, it will index the entire drive contents (Spotlight). If you migrated data from a prior Mac, this can take days with the indexing running in the background and that will take chunk of CPU power and reduce battery life temporarily. Worth noting that Chrome is a resource hog (Google has acknowledged that and says they'll provide a fix), and depending on what you're doing any browser can drive the CPU/GPU pretty hard (streaming ads, YouTube, etc.). I would suggest that what you're seeing is normal.

The MacBook Pro uses so much power, you should think of it as battery-capable, NOT battery-operated like your phone.

Your computer performs best when connected to AC power. It can use the full output of the Power Adapter AND when doing especially challenging work will also freely "borrow" power from the battery. In some cases, the charged state may even decline during stressful work.

When used only on battery, your computer has no extra cushion of power, and will perform more slowly. However, for ordinary non-stressful tasks this may not be objectionable (possibly not even noticeable.)

In general, you should ALWAYS connect AC power when it is possible to do so, and only run on batteries (which will be somewhat slower) when no AC sources are at hand. There are three micro-controllers cooperating on battery and charging issues, and your Mac will NEVER over-charge.

A charge cycle is ever-so-slightly destructive to batter longevity. When operating as designed (and not using Battery Health Management) battery charge level is allowed to decline to about 92 percent level before initiating a recharge cycle to top up to about 99 percent.

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Catalina software 10.15.5 for MacBook Pro with T2 chip (2016 models and later) includes a new feature called Battery Health Management. Based on your usage patterns, this widens the hysteresis to initiate a charge cycle at a lower level, and stop before 99 percent.

About battery health management in Mac notebooks - Apple Support

https://support.apple.com/en-us/HT211094

This relaxes the set points around re-charging (based on your usage patterns) and can improve long term battery lifetimes. When active, recharging may stop short of 100 percent charged.

Editing Videos or photos were Not the sorts of activities Apple tested when they tested this machine for battery life.

Chrome is a notorious resource hog, and has not been updated in any meaningful way for a long time now.

You could get longer battery life from using Firefox, much longer from Safari (because its features are more integrated with the system).

You should think of your MacBook Pro not as a battery-operated device, but as a battery-capable device. When near AC power, you should plug it in.

These Apple User-to-User Community Forums are great for brainstorming and occasional problem solving with other users.

I am not an Apple employe, I am an Apple User, and I am not defending no corporation.

I am trying to tell you, User-to-User, that the experiment you set up is NOT reasonable, and that the "inadequate" results you obtain are expected, because the setup differs from what Apple tested when they made their claims of battery life.

Chrome is a well-known resource hog. Its consumption of everything in your Mac is infamous. You can not do web Browsing with Chrome and expect the same results Apple obtained for their marketing materials.

Lightroom was not used when testing battery life. It performance will not be no 10 hours. Not even close.