I have strong opinions on this subject, much of it due to my own experiences. Many divers get trained to the Open Water Diver level and remain an Open Water Diver for many years. Although Open Water Divers can be very safe and experienced, there is so much more to know.
In many of my first dives and in a number of others since, I have had to manage problems. I made a conscious decision when I became Open Water certified to continue on to Rescue Diver as quickly as possible. Best thing I ever did. First, it gave me a base of knowledge that helped me numerous times to be able to handle problems, small and large, before they became emergencies. Even as a relatively novice diver. Knowledge is power and is critical to being a safe diver.
Secondly, the training made me a better buddy. In a sport that requires a second for safety sake, wouldn't you want to be the best buddy your best friend, significant other, spouse or child could have? I've been the buddy that has needed relatively little support from any of my buddies, however, I have had to handle issues that have occurred with a few of my dive buddies. I was glad I was useful in these situations. I am grateful for excellent instructors who taught me well.
Finally, continuously training saved me money! Although the training cost me money, having most of my first 25 dives be training dives, my gear and air were included in the cost as well as having a first rate dive buddy that could handle anything (my instructor) and a dive guide who could take me to the coolest stuff! On top of all this, I received specialized training in various types of diving and experience with different equipment. All this led to my love for diving and has branched me into areas of diving I never even considered when I started. Public safety diving, ice diving, full-face mask diving......I hadn't even consider these areas; nor research diving, self-reliant diving, Under Water Criminal Investigation....these weren't even on my radar; let alone becoming an instructor.
One never knows how far a path may take them, but without knowledge and experience, it can never be more than when first beginning. Be the best dive buddy you can be. Trust me....train through Rescue Diver. Its the best thing you can do for whoever gets paired up with you in the water, and it'll save you money!
Bottom line.....stay in training. Get good.