Bigger images = more storage = more $$$ and a slower site. 10MB images are nice if you're printing them, but for web use it's overkill.
It's not that hard to resize an image, plenty of sites for just that thing if people can't figure out how to do it on their own devices.
I’ve been a coder and operator for web and mobile since ‘98 - I understand your concerns.
But if you read the discussion on the link I provided, you’ll see XenForo can automatically optimize uploaded images to an appropriate resolution and size for the web. In fact, this site already does resize uploaded images. Bottom line, the site won’t be slower.
Besides, bandwidths are nearly universally fast enough these days to display relatively high-res images without a dramatic slowdown for end users.
As for storage costing more money, storage has never been cheaper, and is still trending down. For a site of this size and active user count, I’d be surprised by a change in costs over $10/mo. And the original uploads aren’t stored, only the resized ones.
The real problem is inconveniencing users, and losing out on otherwise good images they would have posted from their phones. See it all the time by guys trying to upload pics of their cues for sale or whatever and saying they can’t.
Even for a guy like me, who knows what to do, it makes me not want to bother. The other day I wrote up a detailed review from my iPhone of the Rhino CF shaft, and uploaded 11 quality pics for it. Had to resize every one of them. Way harder/more time than it should have taken.
The 1MB limit is not appropriate for 2023. No “good” online communities make it this hard. In fact, I’ve
never run into a site that wouldn’t let me upload images from my phone directly. The site will suffer from less quality content submitted, and more confused/annoyed users.