i feel like a good caster really understands a game fully and breaks it down to the common viewer so that they can understand the strategies a team is implementing. Your casting lacks that deep level of analysis, and instead you just mention things that you don't really even need a caster to see.
an example IMO of a very basic, shallow analysis : "they are pushing through big floor"
an example of a more in depth analysis : "I've noticed that there demo always puts stickies and choke, not only that but their scouts just took heavy spam so they will be coming back to the med to buff up, this makes flank poorly watched and easier to push through big door"
ofc i'm a 16 year old who plays in low open, so my opinion might be flawed.