Short answer: Yes, but it's a long tedious process. There's no quick and easy way to merge mods that won't break things.
Long answer:
It is possible to merge mods together but that requires manual work of merging things yourself and ensuring that things don't conflict with each other. Anyone could do it if they know how to use WinMerge and have some knowledge of Twee/TwineScript which is actually easy to understand and adapt to, especially if you already have a fundamental understanding of programming.
As far as I know, there's no some kind of working patcher or mod loader that automatically does this sort of thing.
It's a complicated process because each mod's source files are basically forks of the game's original repo, meaning that any additions or modifications to the game's code are already applied instead of only having files that just contains additions or edits (not containing the entire vanilla source code) like a typical mod would have for a regular PC game.
It makes sense for developers to update their DoL mod this way but it's not really optimal when it comes to merging mods.
This means that you would have to go through a mod's entire repo and compare it to another mod's repo, finding parts of the code that were modified and making sure it doesn't break or replace a feature from another mod as you merge the code. You might even have to rewrite the code instead so it properly accommodates all new features from each mod.
This can get even more tedious if a mod's game version is outdated compared to another mod's game version as the base game's code would be overhauled in newer versions which may complicate the merging process. Merging mods is just not a feasible option and you might have to do it all the time if you want your base game and mods to be up to date.
When it comes to graphic replacement mods though, well, that's very easy to do as you just need to overwrite the existing "img" folder which every version of DoL comes with (that isn't text-only).
Merging multiple graphic mods however, there will be a lot of conflicts if most of their files both share the same names so just use the ones that you prefer the most.
