The GP's question was about learning IOS dev. For that, you only need the Mac. There is a simulator built in to Mac dev tools so you don't have to have an iphone. The developer account also isn't needed to learn. You only need the $99/year account to publish apps to the app store.
You can just use your Apple ID (I think that's what it's called), which is free. Some of the features are only available if you have the $99/year account.
It's possible to build iOS binaries without a mac but you have to collect a bunch of the tools yourself since Apple has made it illegal to distribute them. Of course you can't actually get the app installed on your phone without sending it to apple first (this is what eg cydia impactor does.)
IMO: that whole platform is so extremely user/developer hostile it's better to just avoid it entirely unless someone is paying you to work on it.
- a Mac (with a recent enough version of Mac OS)
- an iPhone with a recent enough iOS
- a 99$/year (iirc) Apple developer account
These things might be a given for people in SV but it’s quite a big upfront cost for most people outside of HCOL areas.
Unless I’m mistaken and you can do without a Mac? But I seem to recall you need to use iCode (or whatever apple’s IDE is called ;)