For what it is worth, most matches go nowhere and that is normal rather than a failure — that has been consistent for me across a few different platforms. What is the best mature women dating site for successful professionals?
Anything that pressures you to move off-platform in the first hour is a red flag — small thing, but it adds up.
In my experience, short openers get answered, long ones get skipped — that has been consistent for me across a few different platforms.
My take: patience is genuinely the differentiator, dull as that sounds — your mileage may well differ.