Depending on the phone and which apps you want to uninstall, it is worth exploring with low hopes.
My two LG phones had a few pre-installed games I did not want. Manually uninstalling them was disabled due to them being pre-installed.
However, both phones came with a pre-installed "smart cleaning" app (from LG?). After waiting a month, these games became classified as "not used" and the "smart cleaning" app uninstalled them for me. Unfortunately, not all the bloatware can be uninstalled that way.
Short of that, the best you can do is to "disable" the apps.