Except, with the Chronicle, we kinda already know the time skip from Wrath to Cata, and Cata to MoP doesn't seem to be that big a gap. WoW starts at Year 25, while Cata ends at Year 29, essentially 4 years after we canonically start our Journey (Which is EXTREMELY fast, now that I think about it). They also got MoP at Year 30 on WoWpedia, so I'm going to judge things based on that.
BFA seems to take place between Year's 33 and 34, since Anduin is 18 by the time "Before the Storm" happens (Which is in Year 33), and Anduin was 10 during Classic (Which was Year 25).
I would like to assume SL happens in Year 35, or at the very least late Year 34, exactly 9-10 years after Classic. Therefore, if you're gonna actually apply logic here...
Yeah, it's been about 5-6 years since Cata.
You're right though, in that it is a lot of time to fix shit. I do think Anduin's trying his best to help out the people of Westfall...though at the moment...he can't really do anything due to being...well...the Jailer's Avatar essentially.