It’s completely unheard of in any professional environment I’ve worked in.
I don't really use texts for work at all in my industry. I tend only to use texts socially . odd occasion where I may send a "I've emailed you. Let me know if it doesn't turn up".
The point is that texting is a silent electronic communication like email and like an email, there shouldn't be any bar to sending one at any time. BECAUSE
If you don't want to be disturbed you can stop it.
Most normal non-dick people I know utitlise their DND function or have a land line for emergencies.
This is a classic situation of where there won't be agreement.
There are two camps:
Idiots who leave their phones on all night and complain if they are disturbed (I still don't get why there is a difference here between emails and texts. If you are capable of altering the alert for your email, it shouldn't be beyond their wit.
The rest of us who will take advantage of down time to communicate when we have a spare moment - which for busy people may very well be outside business hours or late at night.
Fortunately most of my social circle operate the way I do and are non-idiots.
It's probably best if the Phone-On And I'm Too Thick to Operate the DND Function People stick to being frends with each other and the I'm So Selfish I Will Text Outside the Hours of 9am- 6pm People (but my friends don't care because they do it to and have their phone off) stick to being friends with each other.
That way everyone is happy and both think the other camp is full of idiots.