The parts that might eventually fail are all standard. Easily replaced.
The TFT can be replaced too, so it's not really a problem.
It is however a problem that peope expect it to be completely opensource and then discover it is not. Unfortunately it seems even anycubic cannot do anything about this, as it is the supplier/manufacturer of the TFT that is witholding the image resources. Or so I am reliably informed.
Chances are it is trivial to modify the TFT anyway, we just haven't had someone figure it out yet becasue it's easier to plug in another touchscreeen like the MKS, or an old LCD2004 or 12864.
The i3 mega is a good machine. The robust frame and print-out-of-the-box alone make it worth buying. That said it a little expensive, and if you intend to modify it then it's a bit of a hassle.
.... But almost nobody only buys only one printer anyway, so it's a very good first 3dprinter.