The mechanical parts of a car haven't changed much in the last 25 years, and are easy to understand just by watching a few YouTube videos.
The electronics have certainly gotten more complex, but if you can understand basic computer networking and low voltage electronics it's still quite simple.
If you are interested in learning how to fix your own car, there is a great guy who runs an auto repair business on YouTube and his tagline is: "Remember folks If I can do it, you can do it."
My car needed another key. The stealership quoted me >$400 for it. I took it as a personal insult and did the research and ordered an OBD device and also discovered you can order replacement keys on aliexpress, and they'll even cut them for you with a good picture of your existing key. It was actually a fun project and very satisfying when I was able to successfully program and link the RFID chip to the ECU to start the engine.
May not be feasible with more locked-down modern cars which I wouldn't touch with a ten-foot pole, but I was able to fix it for about $150, not including my time of course. But I have the OBD device to use next time now as well.
eBay key fob (new) + local locksmith, easy and no insults!
The other reason i did it is because the dealership and other shops quoted me over 10 times the cost of parts, and I literally did not have the money to take them up should i have wanted to. Car maintenance is expensive, _especially_ at the dealership.