I agree there is some exaggeration on how much the team/manager is holding back Martial but the fact you've mentioned Messi is also why it's not quite black and white.
This is a lazy comparison but it's generally true, look at Argentina; even the GOAT struggles to find cohesion with his superstar team mates and get results for the national team.
You have to give people the tools to succeed and in this case, better offensive support (individually from team mates) and a more efficient system/set up would massively help (i.e better coaching):
1) A full back, who doesn't sh|t himself one-on-one at the back (so he needs cover all the time) or with the ball at his feet and can actually do something with it.
2) We conceded a lot of harmless possesion sure but when your team doesn't have the ball, how are you supposed to make a contribution regularly?
He won a few free kicks, which relieved pressured, put them on the back foot and created a brilliant chance for Lukaku. He was easily our best outfield player. Not to mention he actually covered Darmian quite decently as well.