If you are serious about going offshore then yes it’s very useful... but only if you use it and know how to use it.
First of all get a good radar reflector. Echo max are the best. There is no point in looking if others can’t see you.
I would consider AIS if you don’t want to go the full Radar route, but not everyone uses it.
It was foggy in the haven yesterday, with AIS and Radar I was happy to run at 18knots in the haven and 20+ once on open coast.
Without Radar I’d be 8-10knots.
It’s a tool, but make sure you can use it before you get waste money on a toy...