I'm not so sure about that. It seems like miners are still the majority sellers of BTC,
Define "majority sellers".
We have a daily Bitcoin trade volume between 10 and 20 billion US dollars (according to Coingecko, today it was 19 billion). Every single trade has obviously a "buyer" and a "seller".
Miners get 144 BTC per day, which are currently (at $40.000) about 36 million USD. This is between 0.1 and 0.3 % of the total selling volume. (I ignore transaction fees, as they aren't relevant if we want to know about the impact of halving).
Of course, what supporters of the "halving scarcity theory" will always say is that a lot of this volume is wash trading or another short-term trading that doesn't really impact in the "scarcity" equation (demand vs supply). But even if 90% was wash trading, altcoin trading and other non-relevant categories, then miners still only account between 1 and 3% of sales. There are many other relevant seller categories, for example payment processors and merchants (which need fiat), hodlers taking profits, mid-term and long-term traders searching for opportunities etc.
I don't say a halving is totally irrelevant. The first halving was very relevant for the price evolution, because it began to drive out "home miners" (above all "laptop/PC miners"), and people had to buy BTC (or invest in expensive mining equipment) if they wanted to get them. The 2016 halving in my eyes also still had a significant impact on scarcity. It drove "supply inflation" down from about 7-8% to 3-4% (per year), which is significant. But since the 2020 halving Bitcoin has less "supply inflation" than major fiat currencies, so any further reduction isn't really that important. In the 2024 halving we'll go down from 1.5-2% to 0.7-1%.
Taking into account these quite low numbers, for me it seems reasonable that other events, such as the ETF approval, technological advancements which boost adoption, or generally "sentiment"-related questions, are much more important than the halving event.
I also don't dispute that on the whole, Bitcoin should become more scarce over time (demand getting up, supply down), due to the rigid emission scheme (if all other parameters on the demand and supply side stay the same*), and that is of course extremely bullish for the long term and explains Bitcoin's steady growth quite well. My problem is the exaggerated importance some people give the
halving event itself (above all the "S2F folks").
*In the very long term, when everybody owns Bitcoin, this may change, but the supply reduction due to key losses etc. should be then enough to compensate for it as the block rewards will be totally negligible.