Why is smartsheet bad?

i never said that Smartsheet is bad. It is great for what we use it for.

it takes a lot of programming on the backend to map sheets together and create dashboards - people think it's easy because it "looks like" Excel, but it is way more complex.

Smartsheets tends to have a steep learning curve. It is promoted much differently than it is. The interface isn’t very user-friendly, which can make it challenging to chart and analyze data. Unless you’re generating reports, there’s no real easy way to analyze the sheets at-a-glance. Plus, it cannot solve all the problems that Jira is able to, nor offer as much connectivity as needed to make it as powerful an option.

This is a question that begs more context. What are you looking to have that Smartsheet does not provide? Conversely, anytime you choose a tool, you need to adopt your processes to adapt to the tool, not vice versa. It's all a very good application for what it does, and if you're asking this kind of a question, it's probably not that Smartsheet is bad, but that it does not align to what you need or vice versa.