Oof. I have 69 games on Steam installed, 11 on GOG, 2 on Epic, 1 on Bethesda.Net, and maybe 10 indies that either came direct or from itch.io. Plus Magic: The Gathering—Arena and Star Citizen. So that's 95?
All that's taking up about 900GB of an SSD. I definitely recommend getting an SSD.
77 Steam Games on my main OS (Fedora Linux). About 10 - 20 GoG on a Win10 Virtual Machine I run inside Fedora. They are the D&D SSI/Gold Box exclusives and the classic Ultima games. I'm moving those over to my host OS, and off the Windows partition, as soon as I get around to it.
How do I do it? I have 2 1TB SSD (an EVO 850 and 860) that I have configured as a single logical volume so I have 1.8TB storage. Very large games like Dragon Quest XI and ESO get removed if I don't play them for a while. While I'm not worried about my SSD lifespan I try and minimize deleting and downloading large games often.