I personally think that the 2015 MBP was the last best value MacBook that would of been the one to last you plenty of years and looks like it has for you. The MacBooks since then have not had much of an noticeable improvement (other than new M1's) and even regressions with the keyboard issues, heat issues etc.

I'm hoping this years gen will be like that 2015 model. But I share your concerns, knowing Apple they will gimp it somewhere like not allowing 2 monitors or limiting to 16GB then have next years model have it which will prob increase sales by a ton long term.