That makes arbitrage trading in the other direction possible. Say: buy XMR at Kraken, sell at eXch. I'm not sure what repercussions that would have.
What I meant was that they could increase the ask price only, while leaving the bid price as it is. The 5% would then simply be the result of the bid/ask spread.Realistic price should be much higher than now, and most shitcoins should have lower or no value at all.
Yep, while I agree that Monero has much better fundamentals from a cypherpunk perspective, typical altcoin investors search for other characteristics. They see that Solana or Avalanche are described in crypto media (which is full of native advertising, of course) potential "Ethereum killers", but have a much lower market cap, so they buy. Or they invest in memecoins or even BRC-20 tokens 
On the other hand, XMR doesn't lose that much value in bear markets. I think on the whole it doesn't perform bad (if we don't take account the Binance delisting-driven dump), it's only less volatile. Solana for example lost 97% in the last bear market. XMR only lost about 80%, not much more than BTC. Tron, which is now hyped again, had its ATH in ... 2018.