There are some "flaws" in the information asked and the information gathered. The decline in guild participation could be because many guilds were not meeting because of Covid. The same would apply to more online purchasing of fabric and tools. If the typical age of a quilter is in their 60s, then that group would have likely been more cautious about gathering in large groups or small shops. Small quilt shops and gathering places most likely would not have the financial ability to put in air filtration systems to help with stopping the spread of COVID. The world, our world included, is going to see skewed stats because of COVID.
On the other hand, in general, what they found in their survey is true for me. Sewing primarily from my stash, more online purchases, retired but part-time employed and use sites such as this to gatherer information and to participate in group activities. I spend more than 10 hours per week in quilt related activities, make more than 10 quilts per year, participate in on-line quilt gatherings and spend far less on materials than in the past. Spending less because of less flexible income? Maybe or perhaps I have all the tools and most of the fabric that I need.
Love digging about in surveys looking for information missed or not asked. Fun in a geeky kind of way.