I was more thinking of a fiat subscription that gives paid relays and filter, but also included sats.
I think a barrier to zaps is getting Bitcoin that you are prepared to use. It is also a barrier to paying for relays. 10,000 sats seems a lot more than $3. If the Bitcoin on an exchange is traded their may be tax implications with disposing it, which is another barrier to mixing use.
If there were a $6 per month subscription that signed you up to paid relays and filter and gave you 10,000 sats per month for example, it would be a familiar feeling, like Spotify or Netflix. People might be willing to pay for a spam free add free experience.