A key area not mentioned in the article is that India is behind China in its home-grown aviation manufacturing industry. The long-in-development next-gen Tejas is a costly disaster by all accounts. While China has been busy developing its indigenous aviation industry via reverse-engineering, India has been content purchasing off-the-shelf equipment from both the west and Russia. No arrangements were even made at licencing the manufacture of components in their deals like what many nations have been making as conditions to a deal.
India's Hindustan Aeronautics (HAL) does produce 80% of the Su-30MKI (or so it says – HAL says a lot of things).
But I agree with most of your comment.
India's ability to develop its own equipment is poor be it the Tejas fighter (current version doesn't offer even the capability of upgraded MiG-21S), tanks (Arjun – massive reliability issues) or even assault rifles (spectacularly failed INSAS which will be replaced by licence produced AK-103).
And Tejas is not next generation as in 5th generation or even 4++ generation (eg Rafale). It is meant to be a light weight 4th generation jet similar to a JAS-39 Gripen.
It has been in development since the 1980s and they still haven't settled on a final production model. There is 1 single squadron equipped with an interim limited capability model (Mk 1 IOC). A second squadron is being formed with a slightly improved model (Mk 1 FOC).
HAL has struggled to build the things so even low level production is horrifically behind schedule.
The actual production model Mk 1A (83 planned) is yet to be properly ordered and hasn't even flown in prototype form. There is also talk of a Mk 2 (150 planned) but that's a paper exercise so far.
Even if it all works out well, the Indians will get the Mk IA in the mid-2020s and Mk 2 in late 2020s-early 2030s. However note this aircraft still isn't as capable as the F-16 Block 50 or 70 or JAS-39 Gripen.
The Indians were planning two stealth fighters – 1 with Russia (FGFA version of Su-57) and a domestic one (AMCA).
The Russian collaboration has fallen over completely.
AMCA was meant to be in service by 2029 but last news in 2019 was that they haven't even signed off on prototype development! Apparently it's future is dependent on freezing of Tejas Mk 2 design.
So India's indigenous fighter program is based on developing increasingly obsolete aircraft (Tejas) whilst China has 1 stealth fighter in service (J-20) and another flown in prototype form (FC-31, not yet accepted for operational use) .
They're almost as bad (or good if you're the seller) as Saudi Arabia in that regard.
Actually selling to India is painful for defence vendors. Most of India's tendering processes are beyond convoluted, open to political machinations and they will then cancel contracts on even mere allegations of corruption, unplanned changes to specifications and political machinations.
Look at the Multi Role Combat Aircraft program designed to licence produce 126 new medium combat jets. This started in 2001. The IAF really wanted more Mirages to supplement its existing fleet.
By the time the Request for Proposal was sent out in 2004 the Mirage 2000 was out of production!
The program then lumbered along to 2012 when the Dassault Rafale was announced as a winner.
However, by this stage the cost of the aircraft has skyrocketed, the Indians wanted France to guarantee work by Indian vendors and the whole program fell in a poo heap! It was cancelled in 2015.
In the end India ordered a mere 36 Rafales in 2015!
So after 14 years, they got a quarter of the planes and no licence production.
This has happened endemically within Indian procurement.