Being the anti-Jira is what made Trello great. If feels like Luke Skywalker just got bought by the Dark Side while claiming that nothing will change -- I'm still with the rebels.
It has eight zillion features, all of them overlapping. It has so many fields, dimensions, views, and reports that I despair of ever getting a setup that usefully matches an actual workflow. The point of a work tracking system is to bring everybody together, but I regularly see people dealing with Jira by having their own separate tracking methods: docs, emails, spreadsheets, sticky notes on the wall.
I like Trello better because it's more straightforward. Less complexity means less chaos and an easier time getting a workflow representation that matches actual workflow.
But personally, I like things that are more straightforward still. E.g., my last company ran almost entirely on index cards, and we were very happy with that:
In other words, like most enterprise software, the experience is highly dependent on how well it's implemented.
Alternately, JIRA as a team board, particularly with remote teams, can be pretty great if you take the time to set it up so that it works for the team (rather than just for the managers or PMs). It can be no more (or at least not much more) cumbersome than Trello, but has a lot of features that Trello lacks.
Your experience will depend on the plugins you've installed, how you've configured custom fields and workflows, your org's SSO policies, the hardware you're deploying it to and how well you keep it up to date (if you're deploying on-prem), etc.
The purpose of software is to specialize hardware to perform a required function. The more configuration is required to do this, the less overall value the software provides for that function.
As a software designer your job is to maximize the sum of that value across all functions that you support. As a software consumer, though, you just want the least possible configuration to perform your required function.
Truth is both tools are just fine. The rest is just people defending their choice as the superior way of doing things.
