Are you using iCloud Drive to sync?
If so, the first launch is a bit wonky. This is because iCloud Drive doesn’t keep everything downloaded by default, and Obsidian needs to read every file. So, it has to work pretty hard to make all of your files available right away.
Generally, this means you should open it, wait a few minutes, then quit and relaunch. You may need to repeat this a few times, especially if you have a lot of files in your iCloud Drive Vault.
Not a nice experience but you should only have to go through it once. No need to delete assets though!