the biggest issue is that they detect thirdparty clients coded as a website parser on their server and just block you. and bypassing this isn't really working well because of the rate limiting.

example: i just did send 3 requests where i first logged in, then asked for the recent posts of a sub.. and already after this 2 requests i got rate limited by error 429 and couldn't send any requests anymore.

so even just requesting the recent posts in a sub is an issue (with spoofed browser useragent). if you use a "legit" useragent it works better, but reddit exactly knows you're using a thirdparty client and can block or ban you whenever they feel like. so it's not really a good solution because every minute reddit could hit the killswitch. just not worth the time to develope a app if it gets killed off then anyway.