People keep saying this but it seems the only people with an actual issue with it are you and tas. Idk what the parkour state was back in the days you guys played but new players play early maps anyway and the difficulties slowly get more hard later in the categories which result in players actually getting better.
Not sure what you mean by "later in the categories" when maps are not sorted by date and most players use the random map selector anyway. If maps
were organized by date added, it would be even more apparent that modern easies are more difficult than early mediums, and et cetera.
As for Pres and myself being the only ones with an issue, perhaps you're referring to us being some of the only members of the MMA actively calling it out. The MMA represents a vocal minority of players who have a vast amount of influence over the server. It is what it is. That group tends to be the most skilled players applying their own views and abilities onto the server as a whole. New or unskilled players are not consulted when "standards shift."
Standards have shifted because there is a certain type of model that is accepted on the server. As a result of the push for "block variety" and "unique jumps," the difficulty of the jumps on accepted maps directly increased. Simple jumps need to be buffed by adding elements of tiers, obstacles, redstone mechanics, neos, and decoration in order to be "good enough." Maps that do not adjust to the new criteria are rejected. That is how the standards shifted.
I don't know about the assumption you're making that players are getting better. The fact is that the minority of players that do improve (usually because they buy a rank and get access to practice mode, speed, and they actually get noticed in chat) are the ones that you hear from, while countless players join for the first time, can't even complete the first map they try because it was buffed by block variance, and give up. You hear about players that "get better" but you don't hear about the ones that don't.