I tried icestudio briefly a while ago. I can't remember whether it was on the Blackice II or TinyFPGA BX board, or both.
Most of the projects I work on are things like retro computers, soft processors, SoCs, oscilloscopes, logic analysers, etc., and they are too complex to be done with a visual editor.
When I used icestudio, I did not like the way it generated verilog identifiers that could not easily be tracked back to the GUI source. I don't know if that has changed. The tool seemed good for learning about simple digital circuits, but not for projects of any complexity. A lot of my projects are ports of existing cores written in verilog or translated from VHDL. It would not be easy to use icestudio for any of those.
Also, I am increasingly using higher-level languages like SpinalHDL and migen.
Other people, who want to implement fairly simple projects, and are not keen on using programming languages, may well find icestudio useful. It is very good that such an open source tool exists.