That's a good question and I commend your understanding of the many protections in place to protect the buyer. The seller, by contrast, has few protections and is exposed to increased risk in additional to financial consequences when an attempted purchase fails.
It should be understood that the Earnest Check is not a piece of paper in a folder. IT WILL BE DEPOSITED BY THE ESCROW COMPANY. This small reality keeps 'jellybean' buyers from plastering home owners with purchase offers they have no intention of honoring.. Without this requirement, the consequences could be costly to homeowner, and no cost to a buyer.
A second aspect to the Earnest Money is a demonstration of your ABILITY to buy. A buyer needing 3% assistance from the seller, minimal down and NO Earnest Money will likely be incapable of adjusting to other bids or the predictable low appraisal.
There is a minor inconvenience in getting the money back but as you point out, not much
Add it up and this buyer could be a very weak buyer.
However, as you pointed out, a no risk, robust Earnest Money can tip the scales favorably in a buyers direction. It boils down to 'Do you want to sabotage your purchase offer?" Being stingy with 'no risk money, is not a beneficial start. Be acutely aware of what Alan advised...don't bet all your eggs on "NO RISK" Know what you are signing.
Best of success to you