Congratulations on your 300th order on Fiverr, Jennifer. That is a good milestone after only 18 months. I am also a freelance writer/ghostwriter there and am approaching my 800th completed order, but I have been there longer.
The first couple of years were slow, but I did find demand for my work really took off with the start of COVID, and I have barely had a day without new orders since. I love Fiverr, and would never consider selling my services through any other freelancing site.
Your advice to new sellers is very good. Many niches are oversaturated with sellers, but there seems to be plenty of work for quality writers.