Laptops were much more modular back in the day and you could replace most parts (even the screen). Since capitalism breeds innovation, laptops became plastic bricks with planned obsolescence that couldn't be repaired easily. Apple computers were so much more customizable but now they are just metal bricks.

Frameworks are really expensive, you could try buying used models or their older gen ones and then slowly upgrade from there. Old thinkpads (like decades old by now) allowed you to swap thing a lot of things but their age is showing. The most you'll get outside of that is being able to replace the RAM/SSD/battery.