Finnish and Estonian are synthetic languages now. While the Proto-Uralic language ancestral to them both was more agglutinative, the system of consonant gradation (and subsequent loss of consonants) as it developed in these languages means they are no longer very agglutinative.
In a purely agglutinative language you only have to memorize one stem for a word and then you can add all case endings to that one stem. In Finnish, you have to memorize at least two stems (strong and weak stems). In Estonian, things are even more complicated.
Consonant gradation/assimilation happens at the surface phonology and do not affect the morphological ground form. We have a similar voicing assimilation in Turkish; however, devoicing is progressively applied and do not propagate more than one syllable, unlike Finnish.
Finnish and Estonian are synthetic languages now. While the Proto-Uralic language ancestral to them both was more agglutinative, the system of consonant gradation (and subsequent loss of consonants) as it developed in these languages means they are no longer very agglutinative.
In a purely agglutinative language you only have to memorize one stem for a word and then you can add all case endings to that one stem. In Finnish, you have to memorize at least two stems (strong and weak stems). In Estonian, things are even more complicated.