The British deposed the last Burmese king in 1885 and annexed the country. For the monastic order this was not simply a political change: the king had appointed the head of the order, adjudicated its disputes, and funded its examinations, and with him gone that whole apparatus lapsed. A widespread expectation held that the teaching itself would now decay, and the question of who would preserve it became urgent.
Ledi Sayadaw's answer was that laypeople would. He argued that the Abhidhamma, the analytic portion of the canon that had been the preserve of specialist monks, was precisely what ordinary Buddhists needed, because it supplied the categories that make insight practice intelligible rather than merely felt. He wrote for that audience in Burmese as well as in Pali, produced summaries in verse so they could be memorised by people who owned no books, and travelled the country founding associations in which villagers studied together.
The consequence was a change in who Buddhism was for. Meditation had been understood as something a layperson might attempt after a lifetime of merit-making, if at all; his manuals presented it as available now, to a farmer, with a technique and a conceptual map. That inversion, doctrine and practice made portable and put in lay hands, is the single most consequential development in modern Theravada, and every subsequent Burmese meditation movement works within it.