what happens when you stop supporting my mac?

bebai5614 Said:

"what happens when you stop supporting my mac?: Do I need to purchase a new Macbook pro since you have stopped supporting it with updates?"

-------

Take this as a Good Reason to Upgrade:

Updates typically go for 7 years or so (and sometimes longer, depending on dependability by consumers). So, soon enough, things will not be available. M1 is the new processor, which 2020 and after Macs have. So, if anything is of concern there, it may be incompatibility. So, getting a 2019 model is more ideal, if you want to get a somewhat "older model".

That's your choice. I've kept MacBooks long after they were "obsolete" using the software installed on the device.

No, macOS is a very secure operating system so attacks are very uncommon on all systems. If you want an upgrade because you MacBook is slow, then I would definitely go for a newer model.