Tiered link building still works, and GSA SER remains the best software for it. The main issue is ensuring your Tier 1 links don’t get deleted. If Tier 1 collapses, everything you point to it Tier 2, 3, or 4 becomes a waste of time and resources. That’s why many people don’t recommend using GSA SER links as Tier 1: they’re usually weaker in authority and often get deleted after some time. To counter this, you need to constantly rebuild and replace removed links with new ones.
This is why Web 2.0 properties are often used for Tier 1. They’re more stable and carry higher authority, though they can also be deleted. The best approach is to create a few hundred Web 2.0 sites, wait about two weeks, and see which ones survive. Typically, the sites that remain after that period have a 80% chance of staying live long-term.
Alternatively, you can use the Money Robot network. Since those sites are owned by the software’s creator, their links have survived every update and remain indexable. As long as you maintain your subscription, you’ll have reliable Tier 1 links for the lifetime of your campaign. Or if you have budget get PBNs built or pay for guest posts.