They had to do a decent revamp ca. 2016 because that's when all EA Sports titles had to start using Frostbite, which probably required re-tooling or outright re-creating old features because, prior to that all the engine was good for was making action shooters."FIFA 21 source code was stolen"
so nothing of value. knowing EA it was probably the same code for the past 20 years with an annual tart up and port over. Fuck them
But yeah, since then the yearly re-skins and stripping of features in order to keep working on Ultimate Team has only gotten more blatant than in the early 2010's.