Question About Door Striker Mounting in Door Jamb

Post has rubber inside sort of like any other isolator. Wearing door hinges allow more and more hammering on the post. Rubber inside the post hardens with age. The sheet metal eventually fails/cracks. Aftermarket offers a repair kit and some of those did include rivets. I haven't seen those offered recently. Here's the thing though... The crack is always at top edge of the round footprint washer on the striker. The floating nut behind is a huge square block that is not coming out through a round hole.
So... with good renewed hinges, good strikers with rubber inside that isn't brick hard..
braze or weld the crack if you want, install a larger diameter footprint washer to the striker and its good to go for a very long time.
In your case, Now that the plate and rivets are there you could just leave as is. Of course attention to hinges and striker is still required.