From what I've read, Bitcoin now charges high transaction fee and long transaction wait time so it can't presently be used:
a) for a conversion from Bitcoin to cash?
or b) purchases using Bitcoin?

If you are looking for a flash transaction then yeah it is not bitcoin that you are looking for , but there are options for the fee to lower and the transaction time be lesses , by using " LIGHTNING NETWORK" but as i believe this is best for small transaction only and not for the much bigger one like more two digits Bitcoin transaction.