In my "software development" course at university (so, not programming, but every "management" thing around it: unit testing, git, waterfall/scrum, etc), I remember the instructor telling us that the first approach to making your program faster was upgrading the hardware. The more time passes, the more shocked I am at an instructor telling this to his students, to the point that I'm now thinking I might recall a cruder version of what was originally said. In any case, that may be the cause!