A lot of commercial
fishermen used to use Drake ham radios in the NE instead of marine radios. Of course Drake was building those for government
use (embassies, etc.) so they weren't quite ordinary commodity grade. But even then, you could tell from the audio quality who was using a marine radio, and who was using a ham radio.
A Jeep and a McLaren are both cars, they'll both get you cross town, that doesn't mean you should pick one at random though.
Sometimes a ham radio is discontinued because of parts
issues. Like Icom's venerable 706, where the final output transistors were equally venerable, andwhen they were discontinued by their maker...bye bye. Then when Icom found a workaround with a new finals board and a different part, for a while, there was an extension. Bye bye.
Sometimes it is just volume, each product has a price/performance niche, if one doesn't sell...
But again, coming back to the OP's wants. A ham radio requires TUNING to FREQUENCIES and all sort of complicated buttons for sideband select, offset, modes...Where a marine VHF
has simple CHANNELS like a tv set. Pick a channel, call. No buttons to get flummoxed with. And, that handy DSC
function may be available on a new one. In an emergency? When you may have to tell someone else "Go down below and call for help" which radio is more likely to be easy for them?
I'd say the marine radio. Not as flexible, but way fewer complications are possible. And a reputable commercial
vendor should be able to supply a clean used one, too. With a guarantee.