Everything in this world requires competition and challenges so that it could evolve. So if there is nobody to compete with, there cannot be development. This is a serious issue in today's tech world where tech giants like Google, Facebook, Microsoft have gained total monopoly in their fields.
Starting with google, the operating system you use which is android is Google's product (Though the actual operating system is open source the services built on top of it are mostly made by google and are closed source.) ,the phone app you're using is from google, the photos app , YouTube, Calendar, Email, Maps, Podcasts, Assistant etc. are Google's products but no one searches alternative for because they are interconnected among themselves. If you just delete your email account your photos backed up in the cloud , your youtube libraries , your location history and addresses ,your browsing history, bookmarks, your phone book, the services logged in with google, everything will be deleted so, you will not be able to (and will not even consider to) get out of it's system.
Now, lets look at Facebook (Now known as Meta). Everybody uses facebook but no one knowns that there exists platform mastodon, disapora , friendrica, etc which has the same objective as Facebook's. But facebook being a big company knows what to do to not let people escape from their own ecosystem. They saw Instagram as a competition but instead of competing with it they decided to buy it. Now, everybody who were in instagram got connected to facebook services. Similarly , they purchased WhatsApp because it felt like a threat to their own facebook messenger. If they couldn't buy it, they take the main feature of that particular apps and add them to their own. They brought the stories feature and the disappearing messages feature from snapchat, twitter had a heart button they brought a whole range of buttons with different emojis on it saying it's a react button They also bought Oculus which was a company developing virtual reality headsets. As of now, the only way to log in to the headset is by using a facebook account. You can sign-up for a different thing like pinterest (For example) via your facebook account which seems like a easy way but it's not. Because if you somehow lose your facebook account ,now a totally different platform is out of access because it used facebook to log you in.
Talking about Microsoft they are the king in the space of desktop computer operating system. Almost every apps are made for windows, their office suite "the Microsoft office suite " or "Office 365" has become the only office suite that is used by almost everyone even if there exist other suites like only office, libre office, etc. They have their own extensions for files .pptx , .docs, .xls etc which is used by almost every office computer in the planet where the .odf (Open Document Format) which is an open source document format doesn't play well with their office suite so the people using MS office will keep using the same office and doesn't leave them. The OS itself comes pre-installed on computers so no normie would ever change the OS instead they will just keep using what they got i.e. microsoft.
This is just a tip of an iceberg and there is a lot more in this topic. This behavior of big tech companies completely destroys the competition on the market because there remains nothing to compete with when they are the only one providing that service.