Tableau is widely used, but needs more support and functionality

Tableau is very good at what it does, however, what it is able to do is very limited. If you want a simple graph or a simple data table then you are set. If you want one of the beautiful intricate dashboards that you see on the web, then you will have to have nearly 50 sheets populating data or graphics that are then overlaid in a dashboard. This means there are so many points at which it can fail and is a nightmare to maintain.

Tableau does not give you support unless you pay for it. If your organization has purchased Tableau and not support, your best bet is to simply use Google for your issue. They were recently acquired by Salesforce so all of the community help forum posts are missing or hard to find now. Support is simply not something that you get, unless you pay for it.

Tableau Desktop is great if you use "Live Connections". Trying to use data sources is a nightmare. When consuming data for dashboards, it is either a full truncate & reload overnight which can take a long time depending on your data warehouse. Or you can use their Hyper & Rest APIs to automate grabbing new data, but it is append only. This means that if you have data that has changed, if you try to use these APIs you will then get duplicate primary keys in your data. So then you are forced to use the live connection or truncate & reload. So you can't source all of your data in 1 data source as that's too large, so then you are left with several small disparate data sources that you then have to support.