My guess is 3tb by 2025
That's too much look at the progress from 2010 to 2019 the current blockchain size is around 220gb. Since the hashrate keeps increasing every year and there's new miner come up with higher hashrate possibly finding blocks can be found in shorter time.
So my guesstimate is around 440gb. I'm not sure but this is just my prediction.
the avarage time is 10 minutes, if the hashrate keeps increasing the difficulty will follow in 2 week tops