I've been on Upwork for many years too. I can see that it's getting more and more crowded, but I still enjoy bidding there. For me, it's not that hard to stand out, especially after I've built myself a reputation. And I know that if I put in the work and bid for a couple of days, I will undoubtedly come up with at least 2-3 paid trials that I can translate into an extended gig. But I have a three-year-old who's taking up most of my time, so I can't get involved in too many freelance projects. As I said, I love the opportunity of getting a paid project fast once I'm ready to jump in.
If I may add, I also take the time to ask the client a couple of extra, thoughtful questions about his job description. I'm sure that only a few applicants are doing it, which helps me stand out even more. It shows that I haven't sent a canned response but rather carefully read his job description. It sends the message that I'm professional and genuinely interested in getting to know the client's needs to provide extra value.
Also, I found it helps to apply within the first 5-10 applicants rather than trying your luck when there are 30+ applicants already.
And this is the last one, I promise :D - they're testing a bidding version where you can throw in more connects when you apply for a job you really, really, really want to get. Bidding more connects will increase your visibility among the other applicants. Do you know anything about it? Have you gotten the chance to test it?