I know the problem - it was a topic in my friend group too. Honestly, for individuals it's gotten expensive. Netflix costs between 6 and 22 euros depending on the plan, Disney+ is similar, and if you want to add Prime Video or Apple TV+ on top, you quickly end up at 50+ euros a month. For a lot of people it makes more sense to just rotate the services - watch Netflix for a month, then cancel, next month Disney+. Some people do it systematically.
Better alternatives are hard to find. There are free services like Pluto TV or The Roku Channel with ads, but the selection is pretty limited. Piracy is obviously an option too, but you'd have to look into the legal consequences yourself. Realistically: if you want to watch regularly, an subscription probably makes sense, but maybe just for one or two services at a time, and then rotate through them.
Another solution would be to figure out with your roommates if everyone pays separately - then you can all watch at the same time without account restrictions. Some shared apartments handle it through split payment apps like Splitwise so the costs are distributed fairly.