Skip a hole an option? As a single you have no standing at most clubs.
Operationally, there is nothing more obnoxious than a single who believes they are entitled to play through multiple groups.
Sure some will wave you through if it's practical.
One single is not a problem but a series of two's three's and singles can ruin a day for a foursome playing at the appropriate pace.
I've got a member who sprints around with a caddy and always announces his time to me and then complains to me it would've been faster but there's some groups out there "playing slow"
I played a lot of golf as a single growing up, but I played when the course was empty, skipped a hole or two, or patiently stayed back,
Appearing on a tee and assuming you're going through(when more than likely there's another group in front of the foursome) is rude and presumptuous.
The common line is that "there was no one in front of the foursome"-which is rarely true, it's just that the single is unaware of the group/groups ahead playing a pace that involves friends/companions.
I play frequently during at a local club which has a wonderful culture of fast play, fousomes playng in 3:15-3:45 on a busy course.
Usually I go out after the lunch crowd and am the last of 10-15 foursomes. Invariably, around the fiftth hole a stray single or twosome appears having played the first 4 holes in 30 minutes, thinking he has the course to himself, not seeing the steady wall of foursomes playing at a more than acceptable rate for foursomes. Soon, there are two singles, a twosome,another single,and and a twosome all lined up thinking they were going to sprint around for an afternoon round.
There's nowhere for one group to go,much less,3-4 smaller groups. Good time to pair up,meet a friend.
A golf course has limited spots to sell,if every group is a single (or worse yet multiple intermittant singles), less people can use the course at the same time