Agreed. Brought back to life my MBP 2015 last summer (battery replacement, keyboard replacement, thermal paste, etc) and thanks to OpenCore Legacy Patcher, now running latest MacOS versions ensuring at least 3 years more of security patches. Also these machines run Linux and Windows pretty fine
Try to give it a shot first on a dedicated partition if you can, then make the switch (IME, I used the old SSD drive for that, then used the 1TB one for daily usage with OCLP).
Pretty smooth for most users apparently. Good luck, keep repairing and maintaining old electronics!
