Investment by start-ups in internet retail, internet software and social/platform software is decreasing in part by a "big tech companies" which are “eating the ecosystem" by creating a "kill zone" in the market. In other words, these big companies buy the start-ups but do not present, as they are not the founders, an emotional investment in these start-ups and would "leave them to wither on the vine". This can be illustrated with companies such as Google, Amazon or Facebook. For example we can talk about Picasa's case which was an online photo sharing platform bought by Google who used it to create Google Phoros devouring Picasa kn 2016 "In 2016 Picasa was killed off for good".
In addition, founders could hesitate when creating a start-up having on mind the big competitors that exist. This can be illustrated when talking about employee recruitment. Big companies will tend to hire "all the best engineers" given them great payements and working conditions that new founders cannot provide as we can read "Google and Facebook and Amazon are offering unbeatable compensation packages with strong job security and plenty of perks". In consequence start-ups would't get the best employee.
Plus, why would founders invest to face Big Companies? As we can read founders think that big companies "will copy their innovations cheaply" and then make it better as they have more financial ressources than new start-ups so they will be spending money, time and effort just that a big company come and take their idea.
In conclusion investment in start-ups in internet retail, internet software and software market is being reduced and this situation is part formed by the Big Company influence that could try to create a kill zone, copy the start-ups ideas or even try to create a kind of sabotage taking the example in employee and engeneer recruitment where Big companies will offer better payement for example.