I must be a Luddite.
I do use a handheld GPS, but mostly for speed.
As for position, well, I've been sailing off and on for 35 years and, like many sailors, most of my cruising is done within 150 miles of home. That means I know where I'm going, and there's little need to watch a little dot on a screen to tell me where I am.
If I get confused, there are plenty of channel markers and landmarks to help me out. It's all part of the traditional sport called sailing. You need to be able to navigate with your eyes, if for no other reason than for the time when your chartplotter quits.
I have used the map part of the GPS to bail me out for safety reasons in a white-out squall while I was in a narrow channel in the Keys, but that's an exception rather than everyday use.
Many years ago, my daughter did a school science project on GPS and nautical charts. We picked a bunch of spots in Biscayne Bay and the Upper Keys. A significant number of locations and channel markers were off, some by many hundreds of feet.
I wouldn't feel safe watching the dot instead of watching the water.
GPS didn't even exist when I started sailing. You had SatNav, but it was thousands of dollars. You also had Loran, which while cheaper than SatNav, was a lot more expensive than GPS is today and not nearly as accurate the less of a right angle the TD lines crossed at.
When cheap GPS's came out, back in the 90's, I did what you are doing now, with a Magellen 310. GPS had signal degradation, built in by the military back then, that made them a lot less accurate than they are today. I can't recall exactly when they stopped doing that.
But, I got my first GPS chartplotter about eight years ago and I think they are one of the greatest advances in marine navigation I have ever seen.
No tool is perfect, but I love my Garmin GPS chartplotters (I have three now, two on my sailboat and one on my center console).