You still have to use a combination of tools to do it properly. For example, @jamie3000's service finds a LOT MORE PBN's then AHREFs et al, as it is not crawling, rather scraping google. So you need to have a few tools in your arsenal to get the job done.
I also think that ahrefs is the best tool (my favorite at least) for competition analysis. And then some other things depending on your particular analysis recipe, of course, but the main tool for me ahrefs
I think that everyone is aware that a lot of PBN's block search bots including AHREFs, yes. They are still incredibly useful tools though.
If I ran a successful and growing SAAS operation, and had 80% of my revenues coming from 20% of my user base, I would cut 20% of potential future revenue to remove the propensity of the 80% of users who were freeloaders or trial account riders. Basic Pareto, and a smart move by Tim and Co.
Saying "SEMRush is gonna waste Ahrefs" is like assuming BAT will be a top 10 coin. Just wild speculation based off of nothing. Pay to play or get out of the way.
SenRush free package got almost everything i need
Ahrefs might be planning to shut down their service to focus on their planned Search Engine. If they keep their service but launch a search engine, that'd be easy to manipulate as users can obtain their data and rankings.
The reason I posted this thread is I was reading some online opinions and tons of folks mentioned how Semrush's free package does almost everything beginners need. No beginners will use Ahrefs. In the long run this is crazy.