No surprises here. Just like the lockdown on iPhone screen and part replacements, Macbooks suffer from the same Apple’s anti-repair and anti-consumer bullshit. Battery glued, ssd soldered in and can’t even swap parts with other official parts. 6000$ laptop and you don’t even own it.
This “iPhones start slowing down” myth is just that - a myth.
No it’s not, I’ve owned several.
So have I. In fact I’m typing this from one that’s coming up on 2 years old while my wife’s is coming up on 4. Both still run like the day they were bought.