Keyword Tool is the best YouTube keyword tool alternative. It uses YouTube autocomplete feature to generate highly relevant long-tail keywords about a particular topic. YouTube autocomplete, just as Google autocomplete, was created to make the user experience better. It helps users find videos faster by recommending related keywords when they start typing in their search query.
Now keep in mind that, based on their stated crawling guidelines, the stronger links from stronger sites tend to get crawled more frequently so the spammiest of the spammy link approaches might not get picked up on. For that level of deep research a historical report from Majestic SEO and a link status checker, like Advanced Link Manager, is likely a better bet.
Ahrefs is incredibly comprehensive and straight forward. From keyword discovery to site audits I use ahrefs for all my SEO needs. It's the first SEO program I was introduced to when starting me SEM management career and has proven to be the best time and time again. I've used their competitors liker moz, SEM rush, and a couple other services- none of which have come close to stacking up.
The thing that I liked the best about Ahrefs is that it contains a huge database of backlinks when I've checked my own website and my competitor's websites. This has allowed me to dig deeper and find out their exact linkbuilding and SEO strategies. Ahref contains a lot of tools and features that will make the life of an SEO professional or webmaster who wants more search engine traffic a lot easier. One of these features is the batch analysis feature. Basically, instead of entering your competitor's backlinks one at a time you could actually enter it once. This allows you to quickly check on the SEO metrics for a lot of competitor URLs in just one click.