Phone to phone is a bit of a bummer... Notably if you lose/break the old one.
There are many options to back up and restore, most are automated and transparent others allow for more subtle user preferences, phone to phone is just very convenient when upgrading for most but Google and Samsung cloud back-ups are always there amongst others
Samsung Kies died ages back BTW
The only major difference to say Iphone back up are
Most key passwords like email, onedrive, have to be re -entered for security, depending on what you have installed previously
3rd Party apps are automatically downloaded from playstore based on your installed list so you always have latest versions. The apps only, user content and settings are backed up and restored
Samsung have an extreme secure area "Safe" that is completed segregated to main phone where business, or personal apps and 2nd accounts etc can be run plus all the normal personal files and photos etc, this has its own secure back up routines to cloud that are separate
Samsung phones allow many options on what you back up or restore including previous phones that can be used on any other phone of your choice
Because of all the customization possible on Samsung and android phones the restore process is much better these days even if you try and use say your S9 back-up to a S21 it will try its best to get close to configurations, newer phones and upgrades need little fiddling to get the same look/layout as previous, same model to model restore even better
For those that use 3rd party launchers and other unique customizations you can always back up to SD/PC just for the layout config then restore over with just current msg's, phone logs, contacts etc , so everyone is covered