The password of the dropbox is of the same size, and special characters as the 1password and Lastpass.
In addition, the keypass database is protected with a master keyfile. The keyfile is made up of up to 5 key####.dat all of which are also within the dropbox. A specific order of the .dat files must be combined to make the master key, and not all of the keyfiles may (or may not be used).
Using multiple files as key file is overkill and i doubt anyone will successfully crack it (at least not in distant future or very big cost). I expect most KeePassXC user only use password or/and single key file with default encryption configuration.