It's not "necessary", though with several different people who might be having a bunch of different games all on there at the same time, it might be worth it.
Amazon has pretty good Cyber Monday deals right now on the Samsung 980 Pro (both the 1TB and 2TB), which is the drive I got to put in my PS5. So might be a good time to grab one (just be aware you'd need to get a separate heatsink to put on that drive).
Edit: actually that listing also has the option for the version that comes with a heatsink, but the 2TB version with it isn't on sale, and the extra $30 they want for the 1TB with heatsink is a little steep considering you can probably get a 3rd party heatsink for like $10-15. Though maybe the extra $15-20 is worth it for you to not have to deal with the hassle of installing the heatsink yourself, depending on how much you like playing with tiny screws.