I've never heard of Metabase. From the GitHub page, I can see it's very popular and looks great!
I'm watching videos on their website and it looks like, that Metabase uses browser as a front end, SkyAlt is native. I'm not sure If you can create/edit tables/columns in Metabase, it looks more like a "import data and create dashboards". SkyAlt is more like Airtable meets Tableau.