In any busy controlled airspace it has never been likely to get flight following, practice approaches, touch and go, etc, and as far as I know controllers have always been allowed to reply to all
of these requests with “unable.”
Flight following has always been available (to me) as I believe they'd rather be talking to you than having you wandering around (completely legally) in VFR without communications. They've vectored me for other traffic, and done the same for me.
The others do directly increase workload and regularly get denied at busy airports (some outright "ban" training activity or charge so much as to make it impractical).