Is it normal that my .minecraft folder takes up a large amount of disk space?
Solution 1:
Yes. It largely depends on your playstyle - long-distance exploration can easily bloat your world into many gigabytes; that includes long-distance Elytra flights, especially extensive End raids and hunts for Woodland Mansions. Similarly mapping large swaths of terrain will necessitate generating it.
Another playstyle that quickly bloats the folder is speedrunning random seeds - each attempt will generate maybe hundred megabytes, but these quickly add up over time and may need to be purged periodically.
Modded minecraft can easily bloat the world as both world generation is more diverse and so compresses worse, there are tools in it that allow loading (and as result generating) large swaths of terrain without ever visiting them, experimenting with generating new dimensions will create plenty of data, and farming diverse generated loot and storing it in vast "digital storage" reflects on your disk too.
If you download adventure maps, or maps of popular servers, say, past seasons of Hermitcraft, expect a couple gigabytes from each.
And if you host a server, multiply the typical load by the number of players. The world of 2b2t, the oldest Anarchy server, currently spans nearly 12 terabytes.
Solution 2:
Yes
Minecraft Java (I do not know what the situation is in bedrock) saves the entire contents of each chunk it generates, not merely the differences between the generated chunk and the current status. So simply exploring the world results in a lot of data being generated and saved, even if you don't do anything that changes the terrain in the chunks you explore.
Worse when you upgrade minecraft versions the game encourages you to make a backup of your world. While well-intentioned this can easily leave you with many copies of your world sitting around.
There exists a tool called mcaselector that can be used to select what parts of a minecraft world you want to keep and what you want to get rid of. These can often be used to dramatically reduce savefile size while keeping the builds you care about.