OnShape will restrict the number of active drawings you can work on at a time. It's a simple matter of turning them on and off. Worst part of OnShape is all your work is public, (they are very up front about this), and can't be hidden. But, you can make a single model as complex as you wish. It's always the latest and greatest version of OnShape every time you log in. And it simply works on any platform that can open a web browser. There is even an app for your phone. I don't really use it at home because I live in a very rural area and electricity can be kind of sketchy at times, let alone the internet. So it can be unreliable for me.

Fusion360 is quite popular due to the perceived ease of use. To be fair there are a ton of very good tutorials for it and the documentation is top notch. Having used a few different CAD packages over 30 years, I'm not overly impressed by it - it's not better or worse than any other choice when you start really working it. I don't care for how much of the "good stuff" they have locked away unless you pay to play. But most hobby users won't notice that issue. They just want an .stl to 3D print - which Fusion is pretty slow to output. And because Fusion uses a half-arsed half local/half cloud solution, (Windows only need apply), and it updates on login it is slow to load, which I dislike. Plus if you do lose the internet, it severely cripples your work until you can log back in.

SolidEdge offers a free hobby version and it worked pretty well when I messed with it for a couple of months. It had a SolidWorks feel to it for me. It's a local install and requires no internet to use. I thought the assembly was limited and not always super intuitive. But it's been a few years since I tried it.

I just use FreeCAD now. I like the local install/run. And right now things are changing for the better with it. Lots of new features and more importantly improvements to the underlying code to make things more robust are coming in the development releases. And more and more excellent tutorials are being created and released. If you are willing to learn, FreeCAD offers a full 3D modeling experience.

Overall, you can design rocket ships to the stars with any of the online CAD solutions, well maybe not TinkerCAD. But, like any other free version of commercial software, they will impose limits on us freeloaders. Try one and see if you like them and it suits your needs.