There is no reason for not using LN for small transactions up to $100 or so, which make up to about 25% of current BTC on-chain transactions.
How did you come to the number of 25% ?
I believe way more transactions are effectively sending less than 100$.
Did you just 'count' all transactions with inputs of less than 100$ ? Because that would have been a mistake.
IMO it is pretty hard to get an accurate number.
If i have 1 UTXO with 1 BTC and want to send 0.001 BTC, the input will still be 1 BTC and probably not count towards your <100$ transactions ?
1 BTC has been transacted, but effectively only 0.001 because 0.999 went back to me.
We won't have this 'problem' of getting an accurate number when using the LN.
Based on this i believe way more than 25% effectively are <100$ transactions.