I like dandelions just because they're kinda pretty. I think it looks nice when they're scattered around a lawn. It's texture.
Lawn culture can go jump in a hole, though. It started out as a thing that super rich people would do, basically going "hey, look! I can afford to basically grow an inedible crop just because it looks nice", and now everyone does it. It sucks up water like you wouldn't believe, and all those perfect lawns look like that because they've been poisoned to kill all the weeds and the bugs and whatnot. The soil quality is usually awful because the grass clippings and leaves are all cleaned up before they decay into the soil, so on goes the huge amounts of fertilizer to keep the grass alive, and since the soil is terrible, it can't hold all that fertilizer and it gets washed out. We're in the process of replacing most of our lawn with wildflower patches and butterfly plants. If you need a lawn to walk on and whatnot, I strongly suggest looking into native grasses or other alternatives. Also- leave the leaves! The grass clippings, too. Don't put a bag on the mower, let the clippings get worked in. Let whatever weeds aren't killed by repeated mowings grow. Insects are dying off all over the world, and lawn culture is part of what's killing them in a lot of areas. All because it used to be a rich people thing to have one.
(rant over)