Amtrak does have delays sometimes but overall I’d say it is reliable. Most of the time the delays are minor (like 5-10 mins). In the ~3.5 years I’ve used Amtrak (usually one ride per week) I have had 2 or 3 major delays. One was due to a severe snow storm and in the other it was a summer storm that knocked a tree onto the tracks. The third time I can’t recall specifically. So I think you may have just had some bad luck. I always plan in some extra buffer (at least an hour) if I need to be sure I don’t miss something important at my destination