how to link quickbase with tableau

It's really not complicated at all. 

You really have three options:
(1) Move the data into a SQL-based database, and then connect Tableau or any BI tool to that database.  There are data services (typically called "ETL") that will do this for you.  A good example is Stitch Data (example: https://www.stitchdata.com/integrations/quick-base/) depending on your volume that could even be free.  I'd recommend if you're not looking to spend a bunch of money, to either use Google Cloud's bigquery or Heroku's postgres as your database. 

(2) Use an ODBC driver for Quickbase (example: https://www.qunect.com/) - Open Database Connectivity (ODBC) is a tool that can run on your machine or server and lets Quickbase "pretend" to be a database - and then just connect Tableau or other BI tool to that ODBC/translator-created database.

(3) Use Tableau's Web Data Connector (WDC) framework to connect directly the Quickbase API - this approach is pretty similar to using an ODBC, but its just using less software and is specific to Tableau (example: https://www.quicktab.xyz/)

Happy to follow up with pros/cons of each if you're still interested.

Out of curiosity, what makes you say it's not for the faint of heart?  

It's complicated to set up.  Too complicated for me to invest the time to learn.

I've used (2) before and it worked well. I couldn't get (1) working - just kept getting errors and no help resolving them. It also looked like (1) was inefficient and showing 10x+ rows aggregated versus the actual size of my QB db. Haven't tried (3)