I think if you have at in high-end restaurants (like Adam’s in Birmingham as a PP mentioned) then you get amazing vegetarian AND vegan options.
If you eat in restaurants that serve particular cuisines (authentic, not chain) based on cultures that restrict meat for either cultural, religious or dietary reasons then you have amazing options.
If you eat in cafes or less formal places you usually get great options - toasted sandwiches, panini, soup, jacket potato, all-day breakfasts etc.
Where you get crap options is mid-range mid-price chain restaurants and pubs where the menu and food costs/profit is calculated at a corporate level, and smaller independent places who genuinely can’t afford to put lots of options on if it’s not making them money or they’ll go under.
I also find these threads fascinating because when you read them there’s basically no right choice for a vegetarian option - you’ll always find people individual vegetarians who hate goats cheese, beetroot, mushrooms, whatever, and then the ones who are bored of risotto, pasta, and so on.
Unless it’s an actual vegetarian restaurant it’s a thankless choice ask to design a general menu that won’t disappoint an individual vegetarian because there’s never going to be more than 2 options for them if they’re lucky and if they don’t fancy either what can you do?