So better spend resources on it rather going for 4th or 5th carrier
Once these ships start their constructions we can look for further carriers
India is not stagnant. As it grows, it will have more resources and will also need more avenues of govt spending. When underdeveloped, govt spending will be focused on basic infra like roads, toilets, railways etc but as these basic infra is created and India moves on, lakhs of crores being spent on infra will no longer be needed once the infra is already in place. So, govt will instead spend the money on tech and defence as they also create employment, circulate resources and generates something useful. This is when more opportunity to make large defence expenditure arises and India will have money for submarines, carriers etc at the same time.
BTW, it is a case of 2035 when the 3rd carrier will be commissioned and Indian economy would have matured