Reports say the Jays made an offer to Gibson who wanted to play in Texas (this was from Shapiro himself), and I think Davidi mentioned the Jays offered more for Porcello than the Mets did but he's from Jersey and decided to sign for less with NY. It's easy to say "just sign (insert player)", but free agency is a combination of overpaying and the player actually wanting to play here. AA thought it was so hard to attract free agents to Toronto that he traded a zillion prospects for players with free agent contracts, and AA is someone who would actually overpay for a free agent if he wanted him bad enough (not as risk averse as Shatkins).
Either way, I don't think the rebuild will last beyond 2020. Next winter, I think the Jays make a real effort to contend. Whether that works or not is a different story, but let's keep in mind this front office wanted to lose games last year. You don't go from outright tanking to blowing your wad in free agency in a span of 12 months unless you have a roster ready for that type of jump. The best plan is to just be opportunistic and improve where you can. If we can sign Ryu, great, but that's probably not happening. Just find the bargains where you can, try to maximize roles, and maximize trade returns. Also, wrap Pearson's arm in bubble wrap.