Over the past 1000 blocks, more than 30% of transactions have been below the longstanding1 sat/vB default min tx relay fee limit. If we plot the actual data, we see spikes around round feerates (1,2,3,4 sat/vB) and a (surprisingly ?) large spike in the sub 1 sat/vB fee rates on the right hand side. We can animate this graph with a 1000 block sliding window for the month of August. There is a wide range in the proportion of blocks which are < 1 sat/vB, but the 144 block rolling average has been on an uptrend in recent months (shown here is data since June, block 900000)

grid.orange.surf

> it only takes one determined spammer to make a tool to allow the less determined to spam. - @Nicolas Dorier This is the asymmetry that many filter proponents seem to miss. Most of the kind of transactions they wish to filter out are created using dedicated software (services / tools / platforms). Developers of such software can rapidly bypass any restriction using open source software like libre relay, which will get their transactions to miners. We already see this, with some platforms offering the ability to select broadcast method from a drop down, including direct broadcast to some miners.