I think for me Alternate Timeline stories are hit or miss. I tend to like it as a trope overall and Tv Tropes has a bunch that fall in the same family but are all slightly different-- Alternate Timeline, Alternate Universe, Alternate History, Alternate reality etc.
I like them when a tv show explores a 'what if' alternate reality scenario in an episode. It can be fun. Grey's had an interesting one and of course the Community episode stands out as one of my favorites.
More often than not if they are really playing with timeline shenanigans as an overall arc it gets muddled and confusing and yeah, they often don't commit to a real swing for the fences change unless they are trying to get creative about a major character leaving.
I will say, one of my favorites was Eureka. In Season one Carter gets an Alt reality timeline episode and gets to experience his idyllic future only to know he can't keep it because it becomes and ethical dilemma. Only for the next four seasons to move him toward just that future in a more natural way (well, not exactly natural because it is Eureka).
ncG1vNJzZmien6fCrr%2BNqamipZWptq6x0WeaqKVfqbyxtcJoaGtrZWl6tcKMramoqJWoeq271Z5knqVdpL9uuM6aq6GdXZq6cLzAoJxobmFk