Not enough space for video clips & pics even after deleting over 1/2 my apps & 2000+ pic & 2 hours of video clips. Barely enough room for new video clips & pics, why????

After I eliminated over half my apps and thousands of pics and hours of video clips, why does it say manage storage or buy more space for $1.99 or $2.99 are they intentionally trying to sell me more space in the cloud? I have thousands of texts and WhatsApp video clips. Should I eliminate a lot of those and will let free me up more space. I feel like trying to sell me more product than what I need even though I did what I was told to do I barely have any space .