You are probably aware that IT startups require engineers. And in Estonia there's only one tech university with a very arguable level of education.
Working in this field for decades, can assure you that for recent years Estonia made a huge progress in importing engineers from Russia, Belarus and Ukraine. Those high-quality engineers actually made it the Startup HQ of Baltics.
As for now, the immigration policy does not permit any work visas for Russian or Belarusian citizens, so this flow is depleted. Ukrainians have stopped coming here few years ago as salary levels were higher in Kyiv and it made no sense in coming to Tallinn. Today they just can't leave the country.
The biggest motivator for engineers from mentioned countries to come to Tallinn was the big Russian-speaking community, which made it "live in Europe, speak in native language" for them. As of today, the pressure on Russian language based education is extremely big, and having kids you want to teach in native language, coming to Estonia for Russian-speaking developers makes no more sense .