I personally not making mobile games or ones with microtransactions. Yet you can basically choose: either there will be microtransaction games for mobile or there will be none. This is not because of developers greed, but because it's the only way to monetize this audience. People voted with their wallet.

Microtransactions in PC games are there for the same reason - because you can't just go and sell your game for $25 if all of the competitors with similar production quality in last 5 years released for $15. Gamers simply wouldnt buy it and nobody care that with inflation $15 back then and $15 now are very different money.

Yet you can put microtransactions in the same $15 game and the same people will pay for them. And you'll reach desired $$$ of profit per copy sold. If everyone refused to pay for microtransactions and would spend more money on buying games without them instead there wouldn't be any microtransactions by now.