Brazil has been been stuck in the Middle Income Trap for decades now like Mexico. At this point, it is hard to see how India can escape from that but first India has to reach middle income first.
Small city-states aside, there has only been two countries with large populations successfully moved from low to 'high' income since the end of World War 2. Poland and South Korea. This is why Poland is so upset at not being included in the G20. Taiwan is not part of statistics. China is at the cusp.
Cutting education is short-sighted. The single best predictor of future productivity is education level. The single most significant determinant of a person's educational success is the country's female literacy level. India is far behind in this measure. 65% for India, 93% for Brazil, and 95 for China. Until India can reach 90+%, it will remain internationally uncompetitive. India rejoined PISA so we'll have better quality-of-education data after the next round.
By definition, most countries cannot escape from the Middle Income Trap because that is what 'average' means. To escape from that, you must have some comparative advantage over your peers like natural resources, location, or human capital or else your standard of living rises around the world's average.
Sadly, China is well aware that if it keeps up the border tension, it forces India to divert precious resources to non-productive use like buying French jets.
Couple of things to add.
In the 1960s/1970s, Brazil (like India) had a period of moderately fast growth.
But then Brazil slowed down and stagnated.
And prior to COVID, India had slowed down to 4.2% like Brazil.
I expect that to be sustained for another 10+ years before India stagnates like Brazil.
But given India's population, it should still mean an India which is economically larger than the USA at that time.
Since 2012, we can see that Indian R&D spending has been steadily decreasing ever year, when measured as a % of GDP.
Given the already low level of Indian R&D spending, you would expect the opposite to happen if India was actually going to become hi-tech, and presumably escape the middle-income trap.
On the PISA results, child malnutrition and physical stunting in India has somehow gotten worse in the 5 years prior to COVID.
It's a surprising development, given that India was posting decent growth rates.
But it makes sense if the upper-castes, elites and Hindu supremacists are intentionally grinding down the 50% of the population who are comprised of the lower/scheduled castes, Muslims and Dalits.
So one could reasonably expect the PISA results in India to be worse than the last time around.