Why Can't Everyone Holding Bitcoin Be A Miner?

I'm not very knowledgeable on coding but the problem right now with BTC is the long lines. Why can't there be a miner company out there that works solely on smaller transaction fees? Would it solved the problem if there was more miners?Why can't someone create a little box that all holders have plugged to their internet that helps the btc economy? even if its slow as hell, in unison it should lessen the traffic, no?