I disagree with you! Looker is more advanced, and that does not mean it is better. Tableau’s tools were MUCH easier for me to make ad hoc analyses with, as well as to create dashboard with. Yes, there were some transformations that I couldn’t apply and had to go to custom SQL or ETL for, but the total time to finish my analyses and produce high-quality live dashboards was much less than with Looker.
(I don’t know why you are being downvoted though, you’re entitled to an opinion same as me)
Lets break it down:
Both are over priced
Lookeer, however has LookerML
Tableau obfuscates all code.
Looker has easier bolt-ons to redshift/postgres
Tableau's BI tool-set is weaker than looker, albeit, wider spread (more mature)
So, I think google got a steal and SF is playing catch-up... at a high cost.
Plus SF's sunk costs in eveything is going to make a 15B buy take at least two decades to pay off....