There are no “real” alternative OS available for apple devices. You can get some IDE “lite” apps like Visual Code, Python Editor, etc. but these a meant as companions to a PC IDE not meant for compiling, linking, testing, etc. You might be able to trade the old iPad for an old laptop you can put a flavor of Linux on.
It’s not the numbers but the content, if they are good natured and have knowledge or entertainment to give the numbers will follow BUT people will also watch a dumpster fire. People with high numbers but lack the rest are not influencers. IMHO, People that go around saying they are “influencers” usually are not and are just bullies trying to throw around weight they don’t have to get free stuff or cause harm.