I'm not sure those figures are that helpful without context though.
There have been by-elections that the Lib Dems weren't particularly challenging for in this period that Reform was a serious runner and rider in.
Plus Reform just does a lot more weird stuff that is newsworthy - they've had the Party Chair resign and rejoin this week alone. Whereas the Lib Dems don't really do much in any given week.
Finally Labour and the Conservatives are taking very public shots at Reform which, again, brings Reform into the news cycle more.