I'd happily use Tor, but the last time I used it (which was ~5 years ago), it was terribly slow for regular browsing (not streaming, or anything considered bandwidth heavy).
The speed is much better nowadays. Unless your unlucky and you circuit has a slow node in it (which the protocol try to avoid if i remember correctly), you should have a decent web browsing experience. Sure, it will be slower than your "normal" connection, but usually not by that much.
Although, if you plan on downloading large files via Tor, you will hit a bandwidth cap fairly quickly. You can look in detail here: https://metrics.torproject.org/torperf.html
Available bandwidth quadruple since 2014: https://metrics.torproject.org/bandwidth-flags.html?start=20...
I typically stay away from Tor when it comes to online banking or finance in general (logging into Amazon with Tor can raise some red flags for example).
In terms of speed, I have noticed personally that Tor has gotten a lot faster. Sometimes you get a slow circuit and have to spawn a new identity / rebuild a new circuit to get a faster one, sort of like 'circuit roulette'.
The rest of my surfing is for fairly innocuous subject matter and using Tor for it would be overkill. Again, Tor would be handy for privately researching general health issues, sexual health issues, mental health issues, etc
Tor is also handy for recon[0] in general too. For me privacy is how you present yourself to the world, and doing recon[0] in a certain community, or (anonymously) 'lurking' in a community is useful before you re-register an account and start posting as the 'real you'.
But maybe you mean if someone using it as the main browsing tool for privacy reasons? This I doubt, since it's indeed slow. I also don't think that Tor is meant to be used as your main browser really.
Tor is also ipv4 so it is a convenient way to get a ipv4 web view inside a ipv6 enabled network, without having to deal with browser plugins or adjust the interface on the machine.