Yep this. SQL Server using RAM is by design. If it's using too much because you're using it for dev work then you can simply limit the amount it can access. RAM is there to be used!
It's a perfectly fine design so long as there's one, and only one, program that is maximizing its RAM usage. When you have many programs (e.g. the browser, Teams, slack, every single electron app), then you get loads of contention.