Did I not see photos of a large bridge being constructed to facilitate the Russian railway from Mariupol onto Crimea? I’m sure I did.
Yes, from Crimea running east, there is a bridge to Russia. From Crimea north, you could WALK all the way north across Ukraine.
Before the war the Ukes even had a little DMZ between Crimea and Ukraine. They dammed up the fresh water canal also.
Now that area is Russian and has been annexed into the Russian Federation, and there is rail crossing it.
The Kerch Bridge is important, but dropping it would not isolate Crimea.
Maripol and Crimea are on the same side of Sea of Azov.... no bridge needed.
You might be thinking of the bridge to Krasnodar, to the east. The Kerch Bridge. But if you look on a map, leave Sevastopol and trace your way north and you’ll see the land link.