The main issue is that implementing authoritarian measures that appear in benefit to your ideological faction (UK Conservatives banning inciteful rhetoric in the 1980s because of frequent riots and unrest) is that they can come back to bite you in the ass in the future (UK Labour party banning
insulting and
targeted language in the mid 2000s amended to the same law from '86). This can happen in reverse, the most recent, quick to backfire example being the push for mandatory bodycams for American police, but then it just gave more ammo to justify FBI stats on blacks and shooting of the unarmed.
A more extreme example (apologies for invoking Godwin's law) is creating a constitution designed to prevent the rise of Nazis (1946, Basic law of the federal republic of Germany) resulting in West Germany being the 1st country (for the 2nd time - Weimer also implemented such laws eventually) to implement hate speech laws in the 1960s, before simply being used as a tool to prevent the rise of ideological opponents and social-right (contemporary Germany). We can also see these laws simply don't work in the face of overwhelming counter-support, such as Weimer Germany's "
Protection of the Republic laws" (1922, 1930) that banned organisations that opposed the republic (targeted the Right-wing mostly as they were implemented by the Social Democrats) doing nothing to stop the Nazis. The first time it passed it was deemed unconstitutional, but since it was passed by a 2/3rds majority, it was allowed to go ahead anyway. In less than 10 years, that support was no longer there.
Some issues, mainly trannies, I can look to being the consequence of speech restrictions and an ideological stranglehold over certain aspects of education, government and the internet. If more people were aware of shit like autogynephilia, I feel there'd certainly be fewer of them around, even if it's just shame keeping a lid on them. Whilst banning porn could solve this (or social media and reddit), I think
shame, or lack thereof, is generally a major issue for a lot of the 'problems' you see in contemporary society (such as furries, trannies, and kids destroying Chromebooks). And any reason for trannies to feel ashamed of themselves was largely buried around the time they started to appear in large numbers online, which you can just as easily blame on the flagrant whiplash to Trump's election win from the Left as you could porn.
Queer theory, NAMBLA, etcetera, all emerged after Conservatism had peaked in the 50s and the 60s saw a massive sperg out in reaction. You saw French writers justifying paedophilia and sex as a construct all for the sake of sexual liberation and other nonsense, the free love movement and hippies in America, etcetera. The French ideas would eventually reach America in the 90s and metastasize into what's now called "Queer Theory", and out of the semi-Conservative 80s, centrist/conservative blend of the 90s to 2010s, it finally flowed into the shit-daffodil we're forced to smell every time we go online. Similar to degeneracy coinciding with sexual liberation, I think the widespread ease and use of the internet caused a similar phenomena. Just as "free love" was trendy in the 70s, porn became something normalised as something funny and normal to most of the internet in the 2010s. The 80s saw a recession from the sexuality of the 70s, so a similar recession might come around soon-ish. 2030s?
Anyway, the death of shame is a cultural thing, and one that'd require a great deal more effort and time to fix, and can't really be forced through rule of law. If banning would fix everything I'd do it in a heartbeat but I don't it'd fix things that require a change in the zeitgeist.
Also: Porn isn't free speech (the idiot who first tried to equate the do is a fuck up) but making the argument for banning porn if we were in the 1960s would have no objection from me personally. But in the modern day it's a different beast, since it's largely online and getting the government and law involved would open the door to more shit, possibly more than we see now where it's just trannies having too much sway (Cloudfare dropping kiwifarms, to name one). The accessibility of it to children is the most justifiable reason to implement a ban and/or ID restrictions, but the counterarguments have been done to death by others already (allowing the gov to decide what you can or cannot access in your own home, how it might envelop other, non-porn things too eventually).
Also offloading responsibility and putting blame on the government and the websites themselves also absolves parents of any responsibility (and shame, remember) in raising their children. Banning porn feels like an ultimately ineffectual and somewhat hollow measure to solve some of the issues we have, and
could be the basis for further restrictions that might actually affect you personally once the opposition gets their hands on them. Normalise shame, normalising shaming, and force parents to take responsibility for what their kids can access, then the problem with porn problem might stop being so pronounced.
The answer to 2025 isn't 1933 (Nazi Germany; too much authoritarian), or 1922 (Weimer Germany; too much freedom) — it's 2030. Hopefully we'll see not too much of either, but not too little too.