Bay Street is what it is, and I say that as someone who lives, works, and walks down the street every day for my commute. I don't expect it to be a glittering showpiece, nor do I think it should be. Save that treatment for University, Bloor, Queen, and other more prominent streets. Could it use improvement, of course. I can think of, for example, the redundant, rusted-out poles that can be removed and replaced from Gerrard south to Queen. Some utility cuts need to be addressed but I suspect they will be next year. More trees would work too (although the new plantings between Wellesley and Grenville are a good start). I noticed recently that long-standing, crumbling curbs and sidewalks have been replaced at College and at Dundas. So it's not all bad. For a Toronto street, it's remarkably well-kept, clean, and orderly. And with each new development, there are improvements to sidewalks and other features. I personally like its quiet, understated character and it does the job it should which is to act as a transition street between Yonge and the U of T/Queen's Park district, as well as act as a useful corridor for intensification (its bones, after all, make it well-suited for this especially in the form of its wide sidewalks).
There are pubs, there are stores, and a mix of uses so calling the street "lifeless" or whatnot is ridiculous, juvenile, and factually incorrect. I've always compared Bay to 2nd or 3rd Avenue in the 70s-80s: nothing glamorous, just meat-and-potatoes apartment houses with amenities nearby, close to subways, and possessing a quiet, workmanlike character. As someone who remembers what the street was like riding along with my dad when he drove the 6 Bay trolley bus, the difference is night and day.