Covid is everywhere and will get everyone. There is no point in travel restrictions and testing international travelers. Thailand probably has ten thousands undetected Covid carriers in their population, a few additional wouldn't make a change. Testing tourists is a waste of time and money, and they make them pay for it!
Re the entry/departure fee. Included in ticket price when leaving by air, but not charged when leaving by land. I left Thailand by land, and I arrived by land, several times (actually, I have left to and entered from all neighbor countries by land) and never had to pay an entry or a departure fee.