I've got an early 2015 MBP and had it for a few years now. Usually I buy a new laptop every 3-4 years and save money each month to put torwards it, but I can't

I've got an early 2015 MBP and had it for a few years now. Usually I buy a new laptop every 3-4 years and save money each month to put torwards it, but I can't help but think that as the next upgrade looms, do I really want to spend £1000+ again on one of these things? Especially now that the latest line of MBPs seems to be pivoting further and further away from what you would normally expect from the 'Pro' line of products. My biggest bugbear right now is memory, and maybe this is just my own failing of not being judicious enough about what things I have open or how may tabs Firefox is running, but I feel even 16GB just isn't cutting it anymore. It feels like laptops have been on a ceiling of 16GB of RAM as an upgradable option for years and I'm not really sure why, is it just the power consumption/battery life that's a concern?