You're comparing the end user to the one doing maintenance. Maintaining an email server is way more work than sending snail mail too. For the end user sending

You're comparing the end user to the one doing maintenance. Maintaining an email server is way more work than sending snail mail too. For the end user sending a transaction is quicker and cheaper than getting your lawyers to draft contracts, maintaining your own books, paying an accountant or someone else to manage/balance the books, coordinating a deal/terms with them, etc. Also there's Proof of Stake which is much more efficient than Proof of Work.