Well, not in fact.
In 2021, 168.8 million tablets were shipped worldwide, a 3.2% yearly growth, according to IDC. The figures are here:
https://www.gsmarena.com/idc_tablet...21_but_things_are_slowing_down-news-52948.php.
Apple shipped 57.8 million iPads, which is a lot. Most of the rest run Android (except for some 9.7 million tablets that run HarmonyOS). So Android should be in about 100 million of these tablets.
There were also 37 million Chromebooks sold, according to IDC, a growth of 13.5% since 2020.
In contrast, 348.8 million computers (both desktops and laptops) were sold in 2021, a yearly growth of 14.8%, also according to IDC. The figures are here:
https://www.idc.com/getdoc.jsp?containerId=prUS48770422#:~:text=Total PC shipments during 2021,Mobile and Consumer Device Trackers.
Of those, 27.7 million were Macs. That still leaves Windows PCs with over 300 million units shipped. And that would not count desktops that were built using spare parts, something which is common among gamers (but which may not raise too much the total).
So, the breakdown would be like this for the year 2021 (I am not considering Linux PCs or Windows tablets, which should not be significant):
Windows PC: 321.1 million
Android tablet: 101.3 million
Apple iPad: 57.8 million
Chromebook: 37 million
Apple Mac: 27.7 million
HarmonyOS: 9.7 million
The total amount of computers and tablets combined is 554.6 million. Windows PCs represent 57.8% of the total. It means that the sales of Windows PCs in 2021 exceeded those of the Macs, iPads, Chromebooks, and Android tablets combined.
If you conclude that most Android tablets, Huawei tablets, and Chromebooks, are cheap disposable devices, which will not last for a long time, or which are not consistently used as a computer replacement, then the alternatives fall even shorter of Windows PCs.
As for the iPad, Windows PCs outsold them more than five times in 2021. Yes, the iPad is a huge business, but, as a platform, it cannot replace the Windows PC industry. In fact, it seems that iPad sales reached a plateau circa 2013-2014 and then declined. According to Lifewire, Apple sold 73.9 million iPads in 2013, and these numbers consistently declined year after year until reaching 40 million in 2019 (before rebounding to 45.5 million in 2020). The website is here:
https://www.lifewire.com/how-many-ipads-sold-1994296.
PC sales declined over the 2010s, but went from about 350 million in 2012 to some 260 million in 2018, its worst year (
https://www.gizchina.com/2022/01/13...ls-but-will-begin-to-fall-after-the-pandemic/). While this is a steep decline, it never reached the levels of the iPad, which, in 2019, sold a little more than half it had sold in 2013. Plus, PC sales rebounded and in 2021 were on par with its best, while the iPad still falls short.
It seems to me that Apple thinks and wishes that the iPad can replace the PC, but the reality shows the opposite.