The text from the image justifies the "maximum mining fee" displayed in the user's client, but it does not explain that even with an acceptable mining fee (e.g., 6.03 for me), the user might still be in the surprising position to pay more than he thought he would. (Because, for example, the decomposer treats a significant amount as dust.) At least that's what I understand.
Although the absolute forfeit maximum is 10,000 sats, the decomposer attempts to waste as little as possible (the simulations from [urlhttps://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-April/020202.html]the mailing list post[/url] measured <500 sats per round, which has improve scaling with more participants). You can check the leftover sats forefeited from each round on
https://liquisabi.com and compare it to the total mining fees paid for that round, it's normally only 10%-20% of the total cost (depending on the mining fee rate of that round).