It's not THAT difficult.
I'm over 30, I don't have a Master's, and I believe I'll be sitting at 508 around August/September.
Currently, I'm at 475 (but losing 5 points on June 6th, since it will be my birthday and I'll be 31).
Sure, I did maxed out IELTS, but besides that, there's nothing really spectacular on my profile: 30 yr, engineer with 3+ years and 2 diplomas. That's it.
The key is focusing in French. I already attempt TCF once, and got C1 for both Reading/Listening, but ZERO for the remaining skills. I'm studying really hard to get a B2 on Speaking/Writing at the end of the summer.
Pretty much anyone can touch the highs 490 or even 500, if they have a strong focus on the language tests. At the end, this is what Canada values the most, at all.