@shouko @nullobsi @amelia
From personal experience them being difficult is more subjective.
An important reason why they are difficult is most people aren't immered in language using these roots. they aren't really more complicated than the utter abundance of latin terms used in english, a learner completely unexposed to them like a child would find them over complicated and ridiculous, say like 'polyamourous', but you encounter these formations so frequently that you get used to them and also break down and have a sense of roots and suffixes.
This does not at all happen for hindi especially for people living in cities all education and almost all other fields completely rely on english and the only exposure in in probably just the 'Prayahvachi' section in a hindi book you are forced to rote (hindi education also fuckings sucks ass) one would really just associate these words with that nonesense crap and not gain the understanding by actually using it.
Compare one's grandparents to one's parents and ultimately oneself here
Seriously I used to despise hindi but sometime (esp with me trying to use shuddh hindi as a joke with my mother) it clicked and things made a lot lot more sense.
Another reason is a change in phonology and preference of tatsama over tadbhava and a lack of understanding explained in the language
while hindi mantains a very close phonology to sanskrit there were darastic changes and frankly some words should highlight and account for it also the normal phonology is very different where the inherent 'a' is ommited often (making things like dharma be pronounced dharam, because it's easier to do than dharm which is difficult for hindi phonology
This is also made much worse by the utter stagnation of literature, esp. language defining literarure which introduce more rules and ability to make word forms almost all languages' grammer and vocabluary are further developed because of this like english itself.
Indian literature esp in the hindi region has been half-dead since the english, the last literature like what I say are from when awadhi and braj were major languages and I suppose the language of the guru granth saheb
Sorry for monologueing so hard but I've been passionatte about this ever since I realized how bad the position of english over indian languages are.
Like consider how fucked up it is that few 'educated' people will rarely ever read a book in their native language.
This genuinely badly effects society causing people to develop an inferiority complex over their culture
Like even after hundreds of years of rule by foreign persian speaking dynasts things never got close to as bad as they are now due to english and that's something which happened very recently due to how the modern schooling system was introduced here british racism during colonisation (read macaulay's english education act) and the the emergence of globalism just around when india became independent (after which things got really really bad in this regard) and it's still being enabled today.
My dad tells me of an anecdote how a japense person on finding success prefers their own language but meanwhile an indian would suddenly become an englishman, a terrible classism that's been introduced here and is somehow accepted (consider how hindi speakers, or hindi medium is considered as something for the lower classes) and the high status of english is central to it. This also means that indians are introduced to an inferiority complex and are rarely proud of their language and culture (compare this to the japanese; the complete opposite despite accepting english)