I never get any responses, until like 3 days later when I check my spam folder and realize my scheduled interview appointment came from some random server that got deleted as spam mail.
It sucks, but this is kinda on you. Spam filters are pretty terrible at what they do. And with everyone and their dog adding "AI" to their security tools, it's only getting worse. There is a fuckton of spam being sent to email addresses all the time. And the spammers are doing their level best to make that spam look more and more like legitimate emails. So, the terrible spam filters and crappy AI are hard pressed to filter out all the crap and not catch legitimate emails. And this problem with false positives is one of the reasons a lot of spam still sneaks through, most of the filters tend to err towards false negatives over false positives. Still, false positives will happen. If you are expecting an important email, you're going to need to dive into the cesspit which is your spam folder regularly and make sure that email didn't end up there.
As for the issues around job hunting, ya that whole process can suck. Depending on your skillset, experience and job criteria, the pool can get pretty small pretty fast. And online job hunting means that companies are getting hundreds of resumes for postings. On top of that, companies have stopped training and don't do anything to build internal talent pipelines. So, if you are earlier in your career, you get stuck in a loop of not having experience, so no one will hire you to get experience. It just sucks and I don't have an answer for you, only to keep plugging away and understand it's a numbers game. Eventually the dice will come up for you, but that "eventually" can really, really suck.