Kinda...
Good milk does improve drinks but it's a matter of scale. For starters a latte for me has at most 3oz of milk. The 6oz version can do more masking and the 16oz bellgrande can hide some dryer lint.
I'd say that the espresso always matters. It's the base of the drink. If it's better the drink has that much more potential.
In defense of milk over espresso I'm willing to bet I impressed more people with milk drinks using 10oz milk, chocolate, whipped cream, and absolutely horrible "espresso" off my stream toy than I ever could with a killer 4oz small milk latte. So I understand the point.
The problem is just that... You can indeed make milk drinks that are tasty with pretty disgusting espresso. You just have to overwhelm it with tons of milk, sugar, chocolate, caramel, etc..etc..
That goal only requires a $50-$100 machine.
Spending any more leads one to curiosity...that curiosity fuels the urge to go down the path, the path contains deep rabbit holes. Quality is invariably a question around some corner and then you are caught in the gravitational pull if your personality is the type to look around the bend.