I have been doing SEO for almost 10 years now and I always rank new sites within a week or 2 tops. How do I do that? I start with ranking low competition keywords first, then work my way up to medium and then hard ones. If sandbox really existed, you couldn't rank low competition keywords either in a short amount of time, but you can. Also, if sandbox existed, viral sites and news would never rank. COVID-related websites would never rank either when the pandemic started and there were quite a few of them who were created just for that purpose. And I could give countless more examples.
If Google put a sandbox in place, they would shoot themselves in the foot, because they couldn't give relevant results for queries never seen before. They also couldn't serve relevant results for queries which have existed for a long time, but the information needs to be updated and none of the sites in the first page haven't caught up with those updates yet.
What people call "sandbox" is actually the amount of time it takes to rank a keyword based on the available competition. There is also the issue of over-optimization, where you are filtered out of the results. Since 99% of people never fix these issues but just blast links, the amount of time it takes for those links to kick in and neutralize the effect of over-optimization is much longer than just fixing the issue in the first place. Add the fact that most of the links are complete garbage and that's why it takes 6 months to start ranking, if ever.
So, the problem is not sandbox, it's the keywords you have selected and the issues you have with your on-page.
If you can find keywords which you can rank with on-page SEO alone and avoid over-optimization, you rank almost immediately (within 2 weeks tops and most of the time even faster). Out of 100 people who do SEO, only 4 or 5 can do on-page properly. If you want some examples of other members, check out threads of phpbuilt & splishsplash.
Also, before you say it, what I call low-competition keywords differs from most people. And no, I don't mean unprofitable keywords with non-existing searches. Again, most SEO-s can't do proper competition research. When they see authority sites on the first page, they get scared & walk away. However, more often than not, those authority sites are not optimized for those certain keywords, so you can outrank them with just on-page alone and no links. There are countless examples of websites on the first page built in the previous 1-2 months ranking for keywords with no links at all. Check ahrefs, you can find them in almost any niche.
Now, for an actual example. Take a popular mobile game and research keywords of the type: "[game] guide", "[game] tips", "[game] cheats/hacks", "[game] free [currency], etc... A lot of those keywords have quite a few searches (thousands per month if you choose a popular game) and the competition in those niches is extremely low. You can create 10-15K words of content spread out between a few pages and rank in 1 week with absolutely 0 links, provided you don't over-optimize. You can still make money with those keywords via CPA/CPI, but you can't build a sustainable business by scamming users long-term. That's another issue and it's related to monetization. But the fact is, you CAN rank for those keywords almost immediately. If sandbox existed, it wouldn't be possible.
Stop blaming your lack of competency on myths that don't exist and instead start learning and testing.
