Use whatever your preferred browser is. 1Password works well with the major ones. And my reasons for preferring some browser are not going to be yours. I will say that Safari has some very strong privacy features built in and obviously works very well on the Mac. Also what may be the "best" browser on a platform today may change in half a year. And you will have your own reasons to prefer other browsers. The great thing about using 1Password is that you can switch between browsers. As others have mentioned, there are a couple of sites (I'm talking about you, American Airlines!) that don't work well with Safari, and when I encounter those, I just pick a different browser for them.
I am not actually going to recommend my setup to anyone, as it is tailored for my peculiar needs, willingness to configure and maintain various configurations, and tastes. But if anyone is curious, a daily basis I use Safari, Brave, and Chrome on my Mac. I use Crome for only for those things where I need to be logged into one of my two Google accounts for some reason or other. To help manage this I have purchased and use https://www.choosyosx.com and set it up to pick browsers based on certain domains and give me the choice of which browser to use when it doesn't. Again, my needs and preferences are not yours.
Again, this is the kind of thing that has evolved over a long period of time, based on need, history, privacy preferences, and desire to tinker. You can make this kind of thing as complicated or as simple as you wish. Start simple and move to more complicated only when there is a real need to.