In increasing standards of living in Victoria 3 could see that you have a lot of peasants. How to lover them? I will show you tips how you could lover peasants fast. The main information which you need is that they need works.
Create jobs for them
If in your nation isn’t enough jobs spaces then people will “work” in subsistence farms. Fast way how to reduce peasants is building farms or plantations because these buildings doesn’t need high educated workers and also reduce the number of “places” where they can be built subsistence farms.
So you will add workspace for your people and they will work and they not be peasants. But is important not to use production methods which lower the number of jobs.
Good on this way is that you have more farms / plantations / fishing or wood production which helps your market with lovering prices. So your standards of living will grow faster.
Focus on education
The important in this case is mathematics which says that not all peasants could works in same number of farms and plantations because subsistence farms provide more spaces to work. So you must focus on education and increasing opportunities to make your residents useful in industry.
You need to focus on literacy with decree like promote social mobility which helps increasee “education access” or also you could focus on education laws like public schools…
… or you could improve your education institutions increase education. It’s easy more educated people => more people which want works in more complex factories and which they want more money.