In my experience, just because you are running agile does not mean you cannot be thoughtful about what gets built, it does not mean you cannot be intentional about quality and resist cutting corners, it does not mean you cannot invest in design systems, it does not mean you cannot invest in UX and built customer-centric tools. It is an excellent methodology to take advantage of to get there. More so than waterfall models.
However, I have also personally encountered the pitfalls commonly mentioned. I've seen bloated backlogs with fragmented pieces of tickets waiting to be picked like in a lottery. I've seen corners being cut to make a release and resulting in fragmented user experiences. I've seen features timeboxed into short sprints only never to be followed up and iterated upon for the next few years.
And all of that — I don't think, is caused by the methodology itself, but instead by us — participants of the process who lack proper comprehension of the core principles, resulting in blindly following a ritualistic process for the sake of it and failing to realize its true potential.
For example, there seems to be an implicit assumption here that any feature has to fit into a two-week sprint. We all know that’s not true — you can take several sprints to deliver one thing. But often there is that temptation to make it a two-week thing and never revisit it again, which is something we do see all the time. In my experience, it takes more wisdom than one might think for a PM/PO to resist that temptation and be able to say yes to multiple sprints, because it means planning.