so far I was told by Apple to replace the phone they do not work on logic boards so in my experience my statement is correct.
Your one-time experience does not entitle you to make a blanket statement about Apple which is not correct.
Depending on the age of the iPhone, the cost of replacing the logic board might be prohibitive and there may have been other items that needed attention.
Rather than simply saying "replace the phone", they could have said something like "the money might be better spent on a new phone".
It is possible to replace a logic board in any iPhone that I've ever seen. I've had a logic board replaced in the past and we speak with users all the time on this site who have done the same.
I came to this community in hopes that others have experience working on iPhone as technicians.....
This is a site for users......not professional technicians. Sure, it is possible that a technician might post, but in 18 years on this support site.....I can say that this is a rare occurrence.
Speaking of relevance, this site is not relevant for you, but you never know. Maybe someone will post to tell you exactly what you have already decided will be the answer.
Good luck.