Is speeding up old laptop still possible?

check whether it can run windows 11 before spending anything. if it can't, something like linux mint runs noticeably better on old hardware than windows 10 now it's out of support. and the ssd swap is easier than it sounds - most ssd makers give you a free cloning tool, so you don't have to reinstall.

Honest answer: if it's still on a spinning hard drive then an SSD is the only change that will make it feel like a different machine. Everything else is a few percent. More RAM after that if it's sat on 4GB. Free stuff worth doing anyway - strip the startup list in Task Manager, and check it isn't just full of dust and throttling itself.