Don't know how good you are with math, but adding one year doesn't add 2-3 years of wait. Adding one year of tanking adds one year of a growth window to the window that was already there. One year adds one year. Simple, right?
The thing in all of this, is that if you look at other teams that went through rebuilds, a period of stagnation is almost unavoidable because young players get added incremenantly and teams can't avoid the ebbs and flow of development.
You can cry and pull your hair out with vigorous discontent, the team will only output to the degree of development it has reached, and as of now, we still don't have the depth nor talent to compete for a playoff spot. Sure, if everything went perfect, we might reach the playoffs, but that level of luck only comes around every so often and is probably followed by a step back the following season, and as we've seen, it still only takes one central player going down to flip the script. It's a testament to our lack of depth and a foreshadowing of the long road ahead before this team actually gets competitive.