My point is: you didn't get phished until you give away any info other than "someone received the email and clicked on the link"
Never heard of drive-by malware attacks? Malicious ads? Zero-click attacks? That link is Schrödinger’s zero-day ransomware attack, which may or may not exist. And there’s no way for you to know which it is, until after you’ve already clicked it. Sandboxing your browser is fine, but they weren’t testing to see if your browser would allow an attack to happen. They were testing to see if you would allow an attack to happen.
The actual method of attack (and any protections you have set up for your browser) is irrelevant, because they’re not testing to see if your browser is hardened. If they were going to do a software audit to see if browsers were vulnerable, you probably wouldn’t ever even hear about it. Because IT would handle it directly, via the access they already have to your company computer.
Tricking you into disclosing sensitive info is only one specific type of attack. The phishing link isn’t checking to see if you’d give info away. If they were testing that, they could do it in other ways, like a fake email from your manager asking for the info. No need to click a link to fail that test. But with the phishing link, you fail the test when you click it because it ultimately doesn’t matter what loads after you click the link. That link exists in a quantum state where every single piece of malware that ever did/will exist can load as soon as you click it.