One common thing I always say when people talk about “millions of years” is
“yeah, what was it like back then?”.
They usually don’t get it. No one currently claiming millions of years was there and is depending on present day processes to conjecture not only the timeframe, but what happened.
Telescopes measure directly, through the standard surveying technique of triangulation, the distance to stars. Within a decade, we will have direct measurements to the center of our galaxy, 30,000 light years away. What do the young Earth proponents have to say about an age of the Universe greater than 6,000 years, based on direct measurements? How does that affect the young Earth hypothesis?
Same could be said for 100 years. What’s your point?