LTB is never easy and when you are in a position where that should happen your mindset at that time is probably not the strongest so it is harder even if you know it is the right decision. There can be times when posters think LTB should happen straightaway and it doesn't always help the OP to be forceful in that view especially if the relationship is abusive and the OPs self esteem and confidence might be at rock bottom.
But I seldom see a LTB that I disagree with. You see it quite often where someone posts about something that doesn't seem too bad and experienced posters (for want of a better word) realise there is a bit more to it and gently ask probing questions and it often comes out that the relationship is a lot worse than initially suggested.
For most people the relationships that they have formed are the only experience of relationships that they have. If they had a dysfunctional childhood and have that as their basis for a relationship then what may seem to others to be a bad relationship is perfectly normal and thus acceptable to them.
To come on here and to have the experience of different people with a huge amount of insight and invaluable advice asking questions of your relationship and making you see things differently can be massively helpful.
Most people will assume that cheating, violence, abuse etc will be dealbreakers. If none of those things are happening then some posters will not consider the relationship bad enough to leave. I would think that the oft quoted advice of "you can leave if it's not working for you" is a thought that some people would not have considered.
Reading some posts on here is seems that there are an awful lot of people in relationships that don't actually make them happy, but haven't considered leaving because they didn't think it was that bad. Far too much walking on eggshells, behaving in a certain way not to antagonise their partner, putting up with constant sulks and not being spoken to for days are not behaviour in a normal, happy relationship.
You might row with your partner sometimes and have ups and downs but you should always be able to count on their support and never ever be scared of their reaction. You should always feel that you are in the relationship together and it is not just you who makes an effort or cares.
Anything that makes you question elements of your relationship is good. If you realise that you are happy with that element of your relationship then you are reassured, if it is found wanting then it makes you question it and you can hopefully work on that with your partner or if not then maybe if it makes you unhappy then you might start questioning whether LTB would really be that bad.
There is some wonderful advice on here and most people posting just want the OP to work out for herself that she is worth more than what she is putting up with. There are many posts that give a lot of insight and help to the OP in working this out.