It's pretty easy if you play lots of games, especially racing, bethesda RPGs, and sports games that have huge file sizes.
For the early parts of the PS4's life, saves were at least 10 MB each until future development brought it down to about 3 MB or so and that was for a 1 GB cloud storage space. Lots of games go well over that.
Just checking right now, here are some example sizes:
Kingdom Hearts III - 671 MB
Rocket League - 105 MB
Taiko no Tatsujin - 44 MB
Switchblade - 197 MB
NBA Live 19 - 94 MB
Spider-Man - 98 MB
Tetris Effect - 98 MB
Hitman 2 - 85 MB
Fallout 4 - 246 MB
Detroit: Become Human - 237 MB
NBA 2K18: The Prelude - 118 MB
Trackmania Turbo - 197 MB
NBA 2K16 - 352 MB
Horizon Zero Dawn - 119 MB
Portal Knights - 269 MB
Puzzle Showdown - 197 MB
Everybody's Golf - 134 MB
Minecraft - 256 MB
Grand Turismo Sport Beta - 249 MB
The Witcher 3: Wild Hunt Complete Edition - 111 MB
LittleBigPlanet 3 - 584 MB
Divinity: Original Sin Enhanced Edition - 115 MB
Nex Machina Beta - 140 MB
Tearaway Unfolded - 315 MB
Mass Effect: Andromeda - 105 MB
Final Fantasy XV - 629 MB
Driveclub - 325 MB
Gravity Rush 2 - 672 MB
Deux Ex: Mankind Divided - 115 MB
Steep Beta - 101 MB
Driveclub VR - 325 MB
Bound - 111 MB
Disney Infinity 3.0 - 325 MB
Nom Nom Galaxy - 126 MB
Looking at my storage listings, I have 16.68 GB of total saves on my PS4, so I'll have more than enough room with this update.