The usual story is that you lack discipline. It is a satisfying story because it is about character, and character feels like something you could fix by trying harder.
The less flattering but more useful story is that nothing about the setup made it hard to quit. You downloaded an app that congratulates you either way. The cost of skipping a day was that a number reset—a number the app itself would happily let you fake.
Meditation gives weak natural feedback
Habits form around friction and feedback. Meditation has very little natural feedback: you sit, and afterwards you may feel roughly how you felt before. No part of the outside world registers that it happened. Compare that with running, where distance is measured whether you like the number or not.
This is why adding more motivation often disappoints. Quotes, reminders, and badges can make starting pleasant, but they do not change what a completed session means.
The more useful addition is measurement that is not entirely up to you. Something that observes the sitting and records what actually occurred, including the days you sat badly or stopped early.
Reduce the number of daily decisions
A practice becomes easier to repeat when its setup is boring. Use the same place, a duration you can finish, and a reminder that arrives before the day becomes crowded. Decide those things once instead of renegotiating the habit every evening.
Then make the completion rule concrete. It can be as simple as remaining on the cushion until a timer ends, or as strict as counting only posture-verified time. The useful rule is one you understand before the session begins.
Change the structure before judging yourself
If you have quit four meditation apps, consider that all four may have had the same structure. You are the constant only because the tools were nearly identical.
A different structure is worth trying before concluding that your character is the problem. Motivation changes by the hour. A clear setup, honest feedback, and a small repeatable commitment can remain when motivation disappears.