I will always have a copy of Practical English Usage on my shelf. I won't be lugging copies of textbooks from when I started teaching.

English Teacher
Hello! I am new to these forums. I just wanted to know; teachers, do you find textbooks to be obsolete now? Do online resources via forums, online books, grammar lessons, etc. outclass textbooks entirely? Or are there some textbooks that are timeless and will always be more useful than the resources mentioned?
I will always have a copy of Practical English Usage on my shelf. I won't be lugging copies of textbooks from when I started teaching.
No to everything.