They have the public betas (available to anyone) but this is a developer beta and requires a developer account (albeit you don't need to pay the $99 anymore). They should probably put it behind the $99 barrier again. It astounds me that people on a site like HN can install a developer beta and then act shocked that it's not 'buttery smooth'. Companies either need to educate people or make it difficult to access beta software again.
To add to what others said - almost every major iOS / macOS release will be slower and drain battery more on the first day after install. The reason for that is they do a lot of indexing of your data and other preprocessing things that enable new features after you install. Once these processes end your device will go back to normal.
I’m surprised Apple does not communicate this fact more clearly to people, as many seem to be totally unaware of it (I do remember seeing notifications on macOS about that though)
>> I am trying it out and aside from being unpolished it’s also slower. My phone used to be buttery smooth. No longer.
IT'S A BETA! Seriously. Of course it's slower. Your phone will run hot. Your battery life will drop. And in three months when it's released it will run nicely - just like each of the last 18 years.
Their developer betas are always unfinished and unoptimized. Once you’ve been through a few of them you become able to evaluate the early versions based on the likely trajectory leading up to release.