Why is the cell theory still accepted today?
Everything holds up, still
1.The smallest living unit is a cell
We haven't found anything smaller
2.All cells arise from preexisting cells
While we have yet to see cells come from anything else, you can literally watch a cell undergoing mitosis and making new cells right now either in a lab or in a video from a lab
3.All living beings are made up of one or more cells
Once again, we see single celled animals in action, have found cells in everything bigger, and have yet to find an organism made up of anything else
The tenants are broad and simple, like, everything is made up of atoms, or the body uses hormones not humors. We have drastically different technology that allows us to better see these things up close and while it happens, and none of these things have been disproved.