The ES is a lot different now - easy to see on the D.O.M. Years ago - it would hit 2 - 4 million contacts per day - now - lucky at times to hit 1.5 million. There used to be Thousands of Contracts on each side. Kind of funny - today - it should be over 2 million contracts - maybe get to 2.5 million by the end of the day.
If I am trading my Discretionary setup - instead of my Algo - I will Adjust to what I see - fast or slow market - I have no preference. When the market is Slow - I see a lot of Price Consolidation - that I call a Range Condition - which is actually one of my favorite trade setups.
I just thought of this - many years ago - I used Tradestation. I did several Posts in the TS Forum - on how I traded the using the D.O.M. - trading strictly off the D.O.M. - with NO charts - Scalping. I haven't had access to TS for years - but if there is anyone interested and they have TS - look up VSTscalper - I think that is what I used in the TS forum.
3-4 million volume day's never were the norm in ES, those days only happen when in abnormal market conditions, just like we had in march 2020 or almost every time the market takes a dive.
I remember those few thousand contracts on each bid/ask as well, but those were the days the average daily range and volume was considerably smaller, like in 2017.
Now i haven't been around since forever but when i check my charts I can't find a period of normal market conditions and average daily volume of 3-4 million.