OP, mysterious slowdowns are Apple's way of saying "time to give us new money." The Apple timetable for Macs is only 7 years and you are at year 10. As Ferris Bueller says at the end of his movie, "it's over... go home."
If you want to keep using a Mac, time to buy a new Mac. What you are experiencing will only worsen as you step forward through time. It doesn't matter if you cling to the last stable version of macOS and dodge new upgrades- the apps themselves will stop working as you are experiencing with Safari not being able to load some websites. That will just get worse... and move beyond only Safari. The apparent "design" is to drive ever-growing frustration until you open the wallet for a new one.
2 OTHER OPTIONS
Otherwise, you are fighting against a rising current "designed" to overwhelm you. Move along with a new Mac, a hack, make that one a "new" PC... or roll on with ever-growing frustrations.
- Hack it with OCLP, which can allow older Macs to run newer macOS at the risk of whatever unique security risks are exposed by leaning on the hack. LOTS of older Mac users do this and seem quite happy with it. OCLP readily proves that older Macs can run newer macOS versions just fine but where's "another record quarter" in that?
- Install Windows 11 on bootcamp and you should have an up-to-date Windows PC good for at least a few more years.
Agreed.
Modern Macs are throwaway machines. This isn't the early to mid 2010's where you could tinker around and upgrade your components. You're supposed to use them for 5 years and then buy a new one. Even if you buy a Mac today, there will be features in the next OS that don't support your "new" machine. Slowly but surely your Mac will be obsolete in no time.
It's a shame but that's the way it is. Anyone who can read can figure out how to use OCLP to extend the life of a Mac. And once Apple drops Intel support, that's the end of that.
Apple: We are committed to protecting the planet.
Also Apple: Your Mac is no longer supported, buy a new one and throw that one out!
Nothing more than Apple greenwashing.