Wow. I grew up in Houston, and I assumed that the smell from these plants was pretty-much unavoidable. It's shocking (and I guess not all that surprising) that this is a choice that manufacturers make.
I guess it really does depend on the economic power of the surrounding communities.
When? I don't know Houston, but I recall in MN a refinery that made the whole area stink for 10 miles around. 15 years latter I went by and the air was great even when driving buy the main gate. Soon after my brother in law got a job at that refinery and he told me that for a years they decided the EPA fines for releases were a cost of going business, but when management decided to clean up they were quickly able to root cause and fix all the issues that caused "releases." Houston can clean up as well, but since I've never been to that city I can't say if things have changed.
Where I live there's been a long running saga around flaring: https://www.bbc.co.uk/news/topics/c6wk2ml6gwzt
When it's lit at night you can see it from up to twenty miles away. Closer in you can hear it. Things have gone back and forwards on mitigations, fines, industrial disputes, and in the end the plant is closing.
When we lived in Edinburgh our flat had a fantastic view north - which included the spire of Fettes College and occasionally the flare from Mossmorran - which together look quite like Barad-dûr and Mount Doom...
I grew up in Louisiana in Cancer Alley[1]. At night, we rarely got to see stars because the flares gave the sky an orange glow.
[1]: https://en.wikipedia.org/wiki/Cancer_Alley
I have a basic understanding of the economics behind flaring, but from the outside it seems like such a waste of energy & hydrocarbons!
Likewise, a lot of the complaints people have about data centers are engineering choices. If companies can get away with it, they'll do it the cheap way.
What could be needed is internalization of external costs. If you release chemicals that cause problems, charge the polluter, and send the charges to those affected.
On a global scale this breaks down, because governments value the lives of non-citizens orders of magnitude below the lives of their own citizens. The US will spend millions to save one expected life at home; it will avoid spending thousands to save one expected life in a third world country.