Don't take the negativity too seriously.
You can click on posters names and read their previous posts on other subjects. After awhile you'll identify posters that give reasonable advice.
You can have a 17-20 year major airline career. Few pilots leave the business despite the complaints so that's telling you something.
The path isn't guaranteed, it can be frustrating, and rough on family life if your wife is used to you being home every night. But few pilots leave so their actions tell a story about the trade offs they've accepted. And due to the supply/demand issues brought about the retiring bubble makes this one on the potentially best, and most stable, periods to become a professional pilot.
The pay can be estimated. The long term trend indicates more pay is more likely than pay cuts.