Yea let's analyze the top 10 fighters at 145 lbs.
1. Cyborg - I challenge anyone to name her top 5 wins. It's impossible without laughing.
2. Coenen - Got choked out by Miesha, lost to Roxanne Modafferi (a fighter with a 19-13 record) and lost to Cindy Dandois. All 135ers.
3. Julia Budd - Got her arm broken by Ronda in 39 and got knocked the fuck out by Nunes in 14 seconds. Both 135ers.
4. Tweet - Lost to Ronda in 49 seconds in Ronda's 2nd pro fight. Another case of a huge 145er losing to a 135er.
5. Arlene Blencowe - 7-5 record
6. Alexis Dufresne - A huge 145er who weighed 150 lbs for her last fight. She lost to Marion Reneau, a 135er. Also lost to Dara Moras, another 135er who could be fighting at 125 lbs.
7. Megan Anderson - Here we go. A decent prospect but with only 3 years of mma experience and no background in any martial art. She's already lost to Cindy Dandois, a 135er.
8. Latoya Walker - a 37 year old soccer mom who took up mma
9. Daria Ibragimova - Lost to 135er Cindy Dandios and heat bunch of nobodies in Europe before becoming a humnan puncing bag for Cyborg.
10. Amanda Bell - A 3-4 record and ranked 10th in the entire world at 145 lbs. That sums up the division perfectly.
None of these ranked fighters are considered good to fill a division. Most of them are old and on the way out and more than half of them have losses to 135ers. You basically have Cyborg and a bunch of tomato cans.
Back in 2011 the UFC had purchased strikeforce and were deciding what to do with the women's divisions. The UFC was seriously contemplating trash canning the 145 lb division due to a lack of quality fighters. This was before Cyborg disgraced wmma by getting caught using steroids. The UFC asked Ronda and Cyborg to drop down to 135 lbs. Ronda did it. Cyborg said she could but never did. In the last 5 years nothing has changed. The division is still shallow and meaningless.
These are all valid criticisms of 145 as it is, but I would say 3 things.
1) Do the same analysis of 135 during Ronda's reign or even now arguably.
2) The only precedent we really have in men's MMA for lack of higher divisions is super heavyweight and the tweeners who just didn't fit in the available 20 lb gap between MW and LHW. Either they got manhandled at the higher weight or they were so sucked in at the smaller weight that they were noticeably sluggish in the cage. Tweener names that come to mind include Dean Lister, Roger Gracie, Hector Lombard, Phil Baroni, and Cacareco. SHWs who had uninspiring careers at capped HW include Sean McCorkle, Tom Erikson, Soa Palalei and Semmy Schilt.Women at 115 who should be 125 are suffering the same issue, MacKenzie Dern being the most recent example. The point is that it's hard to evaluate true 145ers performance at 135 because weight cutting is absolutely a factor in a fighter's performance in MMA.
3) The UFC only recently has offered enough money for female athletes to consider coming over to MMA. The large roster the UFC fields means even if they sign decent women they'll likely sit for most of the year. So there's a general disinvestment in WMMA as little else besides a novelty and that means we get a situation where it seems like there's no one out there when there are enough 145 kickboxers, boxers, wrestlers and judoka who could crossover to build up a division, but can make more in their respective sports. The weaknesses of the top 10 you cite is because few of the fighters on that list have actually had the opportunity to actually fight at 145 so it's an aspirational list at best.
The lack of a division for Cyborg was a choice. I agree she did herself no favors by being on PEDs, but plenty of men have been busted and still been touted as heroes. I think it's too late for her now, to be honest, but she will always show up in arguments as the one no one wanted to fight or could beat. MMA's Lucia Rijker.