This is just an example of some of the merchants that accept steem.

https://steemit.com/promo-steem/@rutablockchain/steem-merchants-is-having-a-birthday-steem-merchants-esta-de-cumpleanos.

Also you can buy stuff with steem via coinpayments.net. If you look at their steem wallet you can see that there is activity on it https://steemitwallet.com/@coinpayments.net/transfers.

By dollar value bitcoin moves more volume than any other crypto but if you compare by the number of onchain transactions steem has double the volume. In fact according to https://blocktivity.info/ there 11 blockchains that process more operations than bitcoin.

I agree that the number of accounts is irrelevant, more important is how many people are using the blockchain and BTC is lagging behind in actual usage.